In January 1996, San Juan County passed an ordinance that banned the use of motorized personal watercraft, subject to certain limited exceptions, on all marine waters and one lake in that county. We are asked to determine whether that ordinance is unconstitutional or violative of the public trust doctrine. We conclude that it is neither and, consequently, reverse the Whatcom County Superior Court’s judgment that the ordinance is void and of no force and effect and remand for entry of an order granting San Juan County’s motion for summary judgment.
FACTS
The Board of Commissioners of San Juan County (Board) held public meetings on September 18 and 19, 1995, for the purpose of discussing what some citizens had identified as a growing problem with the use of motorized personal watercraft (PWC) in San Juan County waters.1 Following those meetings, the Board conducted a workshop with the San Juan County Prosecuting Attorney “regarding drafting of proposed regulations regarding the use of Personal Watercraft in San Juan County . . . .” Ex. 249, at 2 (Ordinance No. 3-1996). On January 23, 1996, the Board conducted a public meeting on a proposed ordinance that was developed at the workshop. One week later, the Board adopted Ordinance No. 3-1996 (the Ordinance). The Ordinance prohibits the operation of PWC on all marine waters of San Juan County, except:
a. During such time that the Personal Water Craft is being used for or engaged in interstate or foreign commerce; and *685that during such use the Personal Water Craft is following the most direct route practicable;
b. During such time that Personal Water Craft are operating under a permit issued by San Juan County or a United States Coast Guard Permit;
c. For emergency purposes when there is a reasonable belief that such use is necessary to protect persons, animals or property.
Ex. 249, at 12-13 (Ordinance No. 3-1996, § 5). The Ordinance also banned the use of PWC outright on Sportsman Lake in San Juan County.
A personal watercraft is defined in the Ordinance as “a vessel of less than sixteen feet (16’) in length that is propelled by machinery, commonly a jet pump, and which is designed to be operated by a person sitting, standing or kneeling on the vessel, rather tha[n] being operated by a person sitting or standing inside the vessel.” Ex. 249, at 12 (Ordinance No. 3-1996, § 3). The Ordinance provides that it will expire two years from the date of enactment unless otherwise extended.2
The Ordinance contained an extensive list of “legislative findings” regarding the nature of the marine environment in San Juan County and the characteristics of PWC. Regarding the marine environment, the Ordinance states:
7. The marine waters of San Juan County has [sic] many species of threatened and endangered species of marine mammals and birds as visitors, migrants or residents that are sensitive to vessel traffic in and among the San Juan Islands ....
9. The refuges and other protected areas offer habitat [where] birds nest and rest and seals rest and nurture their *686young. Birds disturbed or panicked by vessels trample eggs and chicks, knock chicks from nests onto waves and rocks, and expose vulnerable offspring to sun, rain, and predators. Newborn seal pups may become separated from their mothers, crushed by a herd of panicked adults or be forced into cold or swift water prematurely. If the disturbances are continued entire refuge areas may be abandoned by wildlife.
Ex. 249, at 4-5 (Ordinance No. 3-1996). The Board also noted that tourism, which is a “major economic factor” in San Juan County, is “heavily dependent” on visitors who seek “tranquillity” and the opportunity “to view marine life and habitat.” Ex. 249, at 6 (Ordinance No. 3-1996). It made no findings specifically relating to the use of PWC on Sportsman Lake.
The Board’s findings in reference to PWC were as follows:
17. PWCs are capable of high speeds, up to 60 MPH, have a high degree of maneuverability. Operation typically includes rapid changes of direction, rare travel in straight lines, and frequent operation in multiple numbers in a confined area. Operators are expected [to] be in contact with the water either by spray or falling overboard. PWCs are small and have a shallow draft which allows them to be operated at high speeds close to shore.
18. The high speed of a PWC, the rapidity with which it can change direction and the waves and noise it produces cause disruption to other vessels, swimmers and divers and the natural environment. If the operators violate the law, they are almost impossible to apprehend because of the high speed and high maneuverability. Because they rarely travel in straight lines, the vessel speed cannot be easily determined.
Ex. 249, at 8 (Ordinance No. 3-1996).
The Ordinance enumerates multiple effects of PWC about which the Board was concerned:
19. The noise from PWCs interferes with the historical and current uses and enjoyment of the shoreline property. Although unmodified PWC are no louder than other types of *687boats, modifications to PWCs are more common than other vessels. PWCs commonly operate with other PWCs close together for reasons of safety, fun and convenience. As a general rule, additional PWCs operated in the same area will cause the overall noise level to increase. PWC[s] frequently operate in a small area causing conflict with shoreline users. Finally, part of the fun of PWC use is rapid acceleration, deceleration and the jumping of wakes. These operations create an uneven noise, that is louder when the PWC is out of the water, that is objectionable and has been compared in pitch to the sound of a mosquito. These characteristics are not shared by other vessels operated to reach a destination.
20. The operational characteristics of PWCs make them hazardous and incompatible with destination commercial and recreational vessel traffic in and through San Juan County. The maneuverability and ability to travel close to shore of PWCs make them able to harass wildlife and bird life unlike destination power vessels. These attributes are also inconsistent with the protection and preservation of the wildlife which inhabit the waters and refuges of the County. These attributes are also inconsistent with the tranquil lifestyle quality desired by the tourists and residents of the County.
21. The operation of PWCs is less safe and more damaging in San Juan County marine waterways than in other waters because of cold water temperatures, changeable and unpredictable currents, variable tidal heights exposing rocks at different times, floating deadheads, rocks and reefs, and populations of marine life.
22. Accident statistics for PWCs is not yet available for San Juan County, largely because PWC use is only emerging. The evidence from other larger communities where PWC is more established is helpful, however. A report entitled “California Boating Accident Report for 1994” showed that Personal Water Craft made up 13.1 percent of the boating industry, but were involved in 36 percent of all reported boating accidents, 46 percent of the injuries and 17.5 percent of the fatalities and 17 percent of the property damage.
24. The high-speed, high-pitched sound, and ability to *688operate close to shore are characteristics that are unique to PWCs. While the effect of such operation on marine life in San Juan County is unknown, it cannot be beneficial and appear [sic] most likely to be deleterious. Although most wildlife is believed to be quick enough to avoid collisions with powerboats, it is unknown whether all marine life of San Juan County can react quickly enough to avoid PWCs. Without additional evidence to support the safety of PWCs, and given the harmful impact that could result to the County from destruction of its marine life it is found that the best policy is one of “prudent avoidance” and prohibition of PWCs within San Juan County.
25. The Washington State Legislature has enacted regulations regarding the operation of PWCs, which are inadequate for the unique conditions in San Juan County ....
27. Although noise is regulated by RCW 88.12.085, that regulation does not address the cumulative noise of vessels operating in the same area, the annoying impact of vessels that are not destination-bound, and other noise characteristics unique to PWCs.
Ex. 249, at 8-11 (Ordinance No. 3-1996).
Shortly after the Board enacted the Ordinance, a group of PWC users, PWC rental and sales businesses, and a PWC industry association (Respondents), brought suit against San Juan County in Whatcom County Superior Court.3 In their suit they sought a declaratory judgment that “Ordinance 3-1996 is illegal, void and of no force or effect.” Clerk’s Papers (CP) at 2227. They alleged that the Ordinance violates article XI, section 11 of the Washington Constitution because it conflicts with state vessel registration and safety laws, as well as various other general state laws. Respondents also alleged that the Ordinance violates their right to substantive due process, is unconstitutionally vague, and is violative of the public trust doctrine.
*689San Juan County moved for summary judgment, claiming the Ordinance “is a valid exercise of the police power.” CP at 2190. Respondents subsequently filed multiple cross motions for summary judgment on various grounds.4 Following a hearing on the summary judgment motions, the trial court concluded the Ordinance “is in conflict with general laws of the state legislature, including the Recreational Vessel Registration Law, RCW Ch. 88.02” and, thus, violates Wash. Const, art. XI, § 11. CP at 13-14. The court thereafter entered an order denying San Juan County’s motion for summary judgment and granting Respondents’ motion with respect to their “conflict with general laws” argument. CP at 13. The court denied the motion in respect to Respondents’ vagueness argument. The trial court also issued a judgment declaring the Ordinance “invalid, unconstitutional, void and of no force and effect” and enjoining the County from enforcing the Ordinance. CP at 18. The County sought direct review in this court of the trial court’s judgment and its order granting summary judgment. Respondents filed a notice of cross appeal of the trial court’s order denying their motion with respect to the vagueness challenge. We granted direct review.
ANALYSIS
This court reviews an order granting summary judgment de novo, engaging in the same inquiry as the trial court. Greaves v. Medical Imaging Sys., Inc., 124 Wn.2d 389, 392, 879 P.2d 276 (1994). An order granting summary judgment is appropriate only if “the pleadings, *690affidavits, depositions, admissions and all reasonable inferences drawn therefrom in favor of the nonmoving party” demonstrate there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law. Higgins v. Stafford, 123 Wn.2d 160, 169, 866 P.2d 31 (1994) (quoting Peterick v. State, 22 Wn. App. 163, 180, 589 P.2d 250 (1977), overruled on other grounds by Stenberg v. Pacific Power & Light Co., 104 Wn.2d 710, 709 P.2d 793 (1985)); see also CR 56(c). “[Rjegularly enacted ordinance [s] will be presumed to be constitutional,” Homes Unlimited, Inc. v. City of Seattle, 90 Wn.2d 154, 158, 579 P.2d 1331 (1978), unless the statute involves a fundamental right or a suspect class, in which case the presumption is reversed. City of Mobile v. Bolden, 446 U.S. 55, 100 S. Ct. 1490, 100 S. Ct. 1519, 64 L. Ed. 2d 47 (1980); State v. Conifer Enters., Inc., 82 Wn.2d 94, 508 P.2d 149 (1973). Robert F. Utter, Freedom and Diversity in a Federal System: Perspectives on State Constitutions and the Washington Declaration of Rights, 7 U. Puget Sound L. Rev. 491, 508 (1984).
The appeal presents four issues: whether the Ordinance (1) conflicts with chapter 88.02 RCW or various other “general laws” such that it violates article XI, section 11 of the Washington Constitution; (2) is an unreasonable exercise of San Juan County’s police power; (3) is violative of substantive due process; or (4) is unconstitutionally vague.
Article XI, Section 11—Police Power
Article XI, section 11 of the Washington Constitution provides that “[a]ny county, city, town or township may make and enforce within its limits all such local police, sanitary and other regulations as are not in conflict with general laws.” Regarding this “constitutional grant of authority,” we stated in Hass v. City of Kirkland, 78 Wn.2d 929, 481 P.2d 9 (1971):
This is a direct delegation of the police power as ample within its limits as that possessed by the legislature itself. It requires no legislative sanction for its exercise so long as the *691subject-matter is local, and the regulation reasonable and consistent with the general laws.
Hass, 78 Wn.2d at 932 (quoting Detamore v. Hindley, 83 Wash. 322, 326, 145 P. 462 (1915)). While there are limits to the police power, the use of police power by government allows the Legislature to enact laws in the interest of the people. As described in Lawton v. Steele, 152 U.S. 133, 14 S. Ct. 499, 38 L. Ed. 385 (1894), the police power is vast:
The extent and limits of what is known as the police power have been a fruitful subject of discussion in the appellate courts of nearly every State in the Union. It is universally conceded to include everything essential to the public safety, health, and morals, and to justify the destruction or abatement, by summary proceedings, of whatever may be regarded as a public nuisance. Under this power it has been held that the State may order the destruction of a house falling to decay or otherwise endangering the lives of passers-by; the demolition of such as are in the path of a conflagration; the slaughter of diseased cattle; the destruction of decayed or unwholesome food; the prohibition of wooden buildings in cities; the regulation of railways and other means of public conveyance, and of interments in burial grounds; the restriction of objectionable trades to certain localities; the compulsory vaccination of children; the confinement of the insane or those afflicted with contagious diseases; the restraint of vagrants, beggars, and habitual drunkards; the suppression of obscene publications and houses of ill fame; and the prohibition of gambling houses and places where intoxicating liquors are sold. Beyond this, however, the State may interfere wherever the public interests demand it, and in this particular a large discretion is necessarily vested in the legislature to determine, not only what the interests of the public require, but what measures are necessary for the protection of such interests. To justify the State in thus interposing its authority in behalf of the public, it must appear, first, that the interests of the public generally, as distinguished from those of a particular class, require such interference; and, second, that the means are reasonably necessary for the accomplishment of the purpose, and not unduly oppressive upon individuals. The legislature may not, under the guise of protecting the public interests, arbitrarily interfere *692with private business, or impose unusual and unnecessary-restrictions upon lawful occupations. In other words, its determination as to what is a proper exercise of its police powers is not final or conclusive, but is subject to the supervision of the courts.
Lawton, 152 U.S. at 136-37 (emphasis added) (citations omitted). The above quoted language w-as adopted by City of Seattle v. Ford, 144 Wash. 107, 111-12, 257 P. 243 (1927). We have endorsed a similarly expansive view of the meaning of police power:
[Police power] is defined by the supreme court of Illinois, in the case of Lake View v. Rose Hill Cemetery, 70 111. 191, 192 (1873), as—■
“That inherent and plenary power in the state which enables it to prohibit all things hurtful to the comfort, safety and welfare of society. ”
Many definitions have been announced by the courts, but the above, it seems to us, is so terse and comprehensive that we need look no farther for a definition.
State v. Carey, 4 Wash. 424, 427-28, 30 P. 729 (1892) (emphasis added). The police power is firmly rooted in the history of this state, and its scope has not declined. In Covell v. City of Seattle, 127 Wn.2d 874, 905 P.2d 324 (1995), we reiterated, “[m]unicipal police power is as extensive as that of the legislature, so long as the subject matter is local and the regulation does not conflict with general laws .... The scope of police power is broad, encompassing all those measures which bear a reasonable and substantial relation to promotion of the general welfare of the people.” Covell, 127 Wn.2d at 878 (quoting Hillis Homes, Inc. v. Snohomish County, 97 Wn.2d 804, 808, 650 P.2d 193 (1982) (quoting State v. City of Seattle, 94 Wn.2d 162, 165, 615 P.2d 461 (1980))).
We will find the Ordinance consistent with article XI, section 11 of the state constitution unless: (1) the Ordinance conflicts with some general law; (2) the Ordinance is not a reasonable exercise of the County’s police power; or (3) the subject matter of the Ordinance is not lo*693cal. Whether an ordinance is reasonable, local, or conflicts with a general law for purposes of article XI, section 11 is purely a question of law subject to de novo review. See City of Seattle v. Williams, 128 Wn.2d 341, 346-47, 908 P.2d 359 (1995); cf. Washam v. Sonntag, 74 Wn. App. 504, 507, 874 P.2d 188 (1994) (addressing whether statute violates state constitution as issue of law subject to de novo review). In this case, Respondents bear the burden of persuasion.
A. Conflict with General Laws
Article XI, section 11 requires a local law yield to a state statute on the same subject matter if that statute “preempts the field, leaving no room for concurrent jurisdiction,” or “if a conflict exists such that the two cannot be harmonized.” Brown v. City of Yakima, 116 Wn.2d 556, 559, 561, 807 P.2d 353 (1991). Respondents do not argue that the Legislature has preempted the field of conduct governed by the Ordinance but, rather, contend the Ordinance conflicts with various state laws.
“ ‘ “In determining whether an ordinance is in ‘conflict’ with general laws, the test is whether the ordinance permits or licenses that which the statute forbids and prohibits, and vice versa.” Village of Struthers v. Sokol, 108 Ohio St. 263, 140 N. E. 519 [(1923)]. Judged by such a test, an ordinance is in conflict if it forbids that which the statute permits,’ State v. Carran, 133 Ohio St. 50, 11 N. E. 2d 245, 246 [(1937)].”
City of Bellingham v. Schampera, 57 Wn.2d 106, 111, 356 P.2d 292, 92 A.L.R.2d 192 (1960). An ordinance must yield to state law only “if a conflict exists such that the two cannot be harmonized.” Brown, 116 Wn.2d at 561; accord Schampera, 57 Wn.2d at 111 (“Unless legislative provisions are contradictory in the sense that they cannot coexist, they are not to be deemed inconsistent because of mere lack of uniformity in detail. Bodkin v. State [132 Neb. 535] 272 N.W. 547 [(1937)].”). In this case, we must examine whether the Ordinance conflicts with chapter 88.02 RCW, chapter 88.12 RCW, chapter 90.58 RCW chapter 43.99 RCW or the public trust doctrine.
*694The trial court found the Ordinance conflicted with chapter 88.02 RCW the state vessel registration statute. In essence, the trial court found that the Ordinance forbids an activity the statute impliedly allowed.
We have previously addressed a similar argument and established an analysis to be followed. In State ex rel. Schillberg v. Everett Dist. Justice Court, 92 Wn.2d 106, 594 P.2d 448 (1979), we reviewed a Snohomish County ordinance that prohibited the use of internal combustion motors on “certain lakes” in Snohomish County. Schillberg, 92 Wn.2d at 107. A person charged with violating the statute challenged the law “on the ground that it conflict[ed] with [chapter 88.12 RCW].” Schillberg, 92 Wn.2d at 107. We found no conflict and stated:
The provisions of [chapter 88.12 RCW] are concerned with safe operation of motor boats and do not in any way grant permission to operate boats in any place. A statute will not be construed as taking away the power of a municipality to legislate unless this intent is clearly and expressly stated ....
There being no express statement nor words from which it could be fairly inferred that motor boats are permitted on all waters of the state, no conflict exists and the ordinance is valid.
Schillberg, 92 Wn.2d at 108 (citations omitted). Schillberg certainly lays to rest any claim that the Ordinance conflicts with chapter 88.12 RCW. However, we hold Schillberg controls the discussion of whether the Ordinance conflicts with the state’s vessel registration statute, chapter 88.02 RCW
The Legislature did not enact chapter 88.02 RCW to grant PWC owners the right to operate their PWC anywhere in the state. The statute was enacted to raise tax revenues and to create a title system for boats. See RCW 88.02.120. RCW 88.02.020 provides, in pertinent part: “Except as provided in this chapter, no person may own or operate any vessel on the waters of this state unless the vessel has been registered and displays a registration *695number and a valid decal in accordance with this chapter . . . .”5 On its face, the statute prohibits operation of an unregistered vessel. Nowhere in the language of the statute can it be suggested that the statute creates an unabridged right to operate PWC in all waters throughout the state.
Registration of a vessel is nothing more than a precondition to operating a boat. No unconditional right is granted by obtaining such registration. Statutes often impose preconditions which do not grant unrestricted permission to participate in an activity. Purchasing a hunting license is a precondition to hunting, but the license certainly does not allow hunting of endangered species, RCW 77.16.120, or hunting inside the Seattle city limits, see Seattle Municipal Code 12A. 14.071 (banning discharge of a firearm). Reaching the age of 16 is a precondition to driving a car, but reaching 16 does not create an unrestricted right to drive a car however and wherever one desires.
Schillberg states that the Legislature must expressly indicate an intent to preempt a particular field. In this case, the registration statute does not contain language preempting the regulation of this activity to the State. See RCW 46.08.020. We “will not interpret a statute to deprive a municipality of the power to legislate on particular subjects unless that clearly is the legislative intent.” Southwick, Inc. v. City of Lacey, 58 Wn. App. 886, 891-92, 795 P.2d 712 (1990). The San Juan County Ordinance does not conflict with the state’s vessel registration statute; it is a routine application of the police power.
The Ordinance does not conflict with other statewide statutes and laws, specifically chapter 90.58 RCW, chapter 43.99 RCW, and the public trust doctrine. Although the trial court found it unnecessary to address these issues, the parties have thoroughly briefed and argued these issues, and “[w]e may affirm or reverse the summary judgment of the trial court based on our own resolution of the *696constitutional issues.” Washington Ass’n of Child Care Agencies v. Thompson, 34 Wn. App. 225, 230, 660 P.2d 1124 (1983) (citing Simpson v. State, 26 Wn. App. 687, 615 P.2d 1297 (1980)).
The waters of San Juan County are among those regulated by the Shoreline Management Act of 1971 (SMA), chapter 90.58 RCW. However, banning the use of PWC is consistent with the aims of that chapter. Our conclusion is supported by a policy statement in the SMA, which provides in part:
It is the policy of the state to provide for the management of the shorelines of the state by planning for and fostering all reasonable and appropriate uses. This policy is designed to insure the development of these shorelines in a manner which, while allowing for limited reduction of rights of the public in the navigable waters, will promote and enhance the public interest. This policy contemplates protecting against adverse effects to the public health, the land and its vegetation and wildlife, and the waters of the state and their aquatic life, while protecting generally public rights of navigation and corollary rights incidental thereto.
The legislature declares that the interest of all of the people shall be paramount in the management of shorelines of statewide significance.
RCW 90.58.020 (emphasis added). The ban of a certain type of activity is consistent with the “limited reduction of rights” allowed by the statute. Moreover, there is additional language in RCW 90.58.020:
The department, in adopting guidelines for shorelines of statewide significance, and local government, in developing master programs for shorelines of state-wide significance, shall give preference to uses in the following order of preference which:
(1) Recognize and protect the state-wide interest over local interest;
(2) Preserve the natural character of the shoreline;
(3) Result in long term over short term benefit;
*697(4) Protect the resources and ecology of the shoreline;
(5) Increase public access to publicly owned areas of the shorelines;
(6) Increase recreational opportunities for the public in the shoreline.
Here, the Board concluded that “[t]he maneuverability and ability to travel close to shore of PWCs make them able to harass wildlife and bird life unlike destination power vessels.” Ex. 249, at 9 (Ordinance No. 3-1996). It also found that such attributes of PWC are “inconsistent with the protection and preservation of the wildlife which inhabit the waters and refuges of the County.” Ex. 249, at 8-11 (Ordinance No. 3-1996). Thus, the Ordinance appropriately favors “the resources and ecology of the shoreline” over recreational interests, RCW 90.58.020, and is consistent with the statute’s purposes.
The Ordinance does not conflict with chapter 43.99 RCW, the Marine Recreation Land Act of 1964, and its implementing regulations, which are set forth in Title 286 of the Washington Administrative Code. In enacting RCW 43.99.110, the Legislature created the interagency committee for outdoor recreation (IAC) for the purpose of expending the portion of unreclaimed fuel taxes paid by boaters to “acqui[re] or improved marine recreation land on the . . . fresh and salt waters of the state.” RCW 43.99.010(2) (summarizing “mission” of IAC). According to Respondents, because the County has received substantial funds from the IAC, it must keep facilities open to “all motorized vessels.” See Br. of Resp’ts at 55-56 (citing CP at 1759-71; CP at 1133-36 (IAC Guidelines § 4.08(15)(A-D)). The document that Respondents cite as support for this proposition is an agreement accompanying a project grant from the IAC to the Washington State Parks and Recreation Commission for the purpose of developing boating facilities in San Juan County. Although the agreement states that all facilities covered by it “shall be kept open for public use at reasonable hours and times of the year,” it contains no language *698indicating that the County may not otherwise restrict the manner in which the public uses the facilities. CP at 1763. Moreover, the agreement provides that subject facilities are to be operated “in accordance with all applicable . . . local laws and regulations.” CP at 1763. We do not find the Ordinance inconsistent with this agreement.
Since as early as 1821, the public trust doctrine has been applied throughout the United States “as a flexible method for judicial protection of public interests in coastal lands and waters.” Ralph W. Johnson et al., The Public Trust Doctrine and Coastal Zone Management in Washington State, 67 Wash. L. Rev. 521, 524 (1992). The doctrine protects “public ownership interests in certain uses of navigable waters and underlying lands, including navigation, commerce, fisheries, recreation, and environmental quality.” Johnson, supra, at 524. The doctrine reserves a public property interest, the jus publicum, in tidelands and the waters flowing over them, despite the sale of these lands into private ownership. Johnson, supra, at 524. “The state can no more convey or give away this jus publicum interest than it can ‘abdicate its police powers in the administration of government and the preservation of the peace.’ ” Caminiti v. Boyle, 107 Wn.2d 662, 669, 732 P.2d 989 (1987) (quoting Illinois Cent. R.R. v. Illinois, 146 U.S. 387, 453, 13 S. Ct. 110, 36 L. Ed. 1018 (1892), aff’d, 154 U.S. 225, 14 S. Ct. 1015, 38 L. Ed. 2d 971 (1894)). Due to the “universally recognized need to protect public access to and use of such unique resources as navigable waters, beds, and adjacent lands,” courts review legislation under the public trust doctrine with a heightened degree of judicial scrutiny, “as if they were measuring that legislation against constitutional protections.” Johnson, supra, at 525, 526-27.
This court did not expressly adopt the public trust doctrine until 1987, but indicated then that the doctrine has always existed in Washington law. See Caminiti, 107 Wn.2d at 669-70. The doctrine in Washington “prohibits the State from disposing of its interest in the waters of the state in *699such a way that the public’s right of access is substantially impaired, unless the action promotes the overall interests of the public.” Rettkowski v. Department of Ecology, 122 Wn.2d 219, 232, 858 P.2d 232 (1993).
The test of whether or not an exercise of legislative power with respect to tidelands and shorelands violates the “public trust doctrine” is found in the following language of the United States Supreme Court:
The control of the State for the purposes of the trust can never be lost, except as to such parcels as are used in promoting the interests of the public therein, or can be disposed of without any substantial impairment of the public interest in the lands and waters remaining.
Accordingly, we must inquire as to: (1) whether the State, by the questioned legislation, has given up its right of control over the jus publicum and (2) if so, whether by so doing the State (a) has promoted the interests of the public in the jus publicum, or (b) has not substantially impaired it.
Caminiti, 107 Wn.2d at 670 (quoting in part Illinois Cent. R.R., 146 U.S. at 453) (footnote omitted).
We have previously acknowledged that the jus publicum interest encompasses the “rights of fishing, boating, swimming, water skiing, and other related recreational purposes generally regarded as corollary to the right of navigation and the use of public waters.” Caminiti, 107 Wn.2d at 669 (emphasis added) (citing Wilbour v. Gallagher, 77 Wn.2d 306, 316, 462 P.2d 232, 40 A.L.R.3d 760 (1969)). Nevertheless, we agree with the County that the Ordinance does not violate the public trust doctrine because the County has not given up its right of control over its waters. Although the Ordinance prohibits a particular form of recreation, the waters are open to access by the entire public, including owners of FWC who utilize some other method of recreation.
While the Ordinance governs activities more appropriate for general state legislation, the State has failed to act. The San Juan County Ordinance cannot conflict *700with state laws that do not exist. Further, the Ordinance is consistent with the goals of statewide environmental protection statutes. Finally, it would be an odd use of the public trust doctrine to sanction an activity that actually harms and damages the waters and wildlife of this state.
B. Reasonable Exercise of Police Power
The Ordinance must be a “reasonable” exercise of the County’s police power in order to pass muster under article XI, section 11 of the state constitution. City of Seattle v. Montana, 129 Wn.2d 583, 591, 919 P.2d 1218 (1996). “A law is a reasonable regulation if it promotes public safety, health or welfare and bears a reasonable and substantial relation to accomplishing the purpose pursued.” Montana, 129 Wn.2d at 592; accord Thurston County Rental Owners Ass’n v. Thurston County, 85 Wn. App. 171, 181, 931 P.2d 208, review denied, 132 Wn.2d 1010 (1997). “[T]he wisdom, necessity and expediency of the law are not for judicial determination,” and an enactment may not be struck down as beyond the police power unless it “is shown to be clearly unreasonable, arbitrary or capricious.” Homes Unlimited, Inc. v. City of Seattle, 90 Wn.2d 154, 159, 579 P.2d 1331 (1978).
In State ex rel. Faulk v. CSG Job Ctr., 117 Wn.2d 493, 816 P.2d 725 (1991), we announced a two-part test to be employed when determining the validity of a statute passed pursuant to the police power. First, the statute must promote the health, safety, peace, education, or welfare of the people. CSG Job Ctr., 117 Wn.2d at 504. Second, the requirements of the statute must bear some reasonable relationship to accomplishing the purpose underlying the statute. Id.
The Ordinance indicates the ban on EWC is intended to prevent “disruption to other vessels, swimmers and divers and the natural environment,” prevent interference “with the historical and current uses and enjoyment of the shoreline property,” ensure the safety of “destination commercial and recreational vessel traffic,” protect “wildlife *701and bird life,” and further the tourism-based economy. See Ex. 249, at 8, 9 (Ordinance No. 3-1996). The plain language of article XI, section 11, which provides that counties may enact laws to promote “peace,” and “safety,” encompasses two of the objectives enumerated above.
In State v. Satiacum, 50 Wn.2d 513, 520, 314 P.2d 400 (1957), we recognized that a “plenary right” is vested in the state under its police power to enact general laws for “regulation and conservation of wildlife.” Similarly, we found in CLEAN v. State, 130 Wn.2d 782, 806, 928 P.2d 1054 (1996), that the Legislature was within its purview in enacting legislation to “improved the economy of the state . . . and enhanced the fabric of life.” Thus, the ban does promote the purpose of the underlying statute.
Once an ordinance is found to serve a “legitimate public purpose,” we examine whether the Ordinance uses “means that are reasonably necessary to achieve that purpose.” Rivett v. City of Tacoma, 123 Wn.2d 573, 581, 870 P.2d 299 (1994) (quoting Presbytery of Seattle v. King County, 114 Wn.2d 320, 330, 787 P.2d 907 (1990)). A law must “beard a reasonable and substantial relation to”6 or “be reasonably necessary to protect”7 the public health, safety, morals, or general welfare.
Respondents argue that “ ‘[cjommunity displeasure,’ ‘generalized complaints’ or ‘public distaste for certain activities’ cannot be the basis for governmental action.” Br. of Resp’ts at 37 (citing Maranatha Mining, Inc. v. Pierce County, 59 Wn. App. 795, 804, 801 P.2d 985 (1990)). Respondents urge us to follow the reasoning of Steier v. Batavia Park Dist., 283 Ill. App. 3d 968, 670 N.E.2d 1215, 219 Ill. Dec. 327 (1996), appeal denied, 171 Ill. 2d 586, 677 N.E.2d 972, 222 Ill. Dec. 438 (1997), in which the Illinois Court of Appeals considered whether an ordinance prohibiting FWC from using a boat launch violated language in an Army Corps of Engineers’ permit under which the launch *702had been constructed. In concluding the ban violated the permit’s requirement that the city allow “the full and free use by the public of all navigable waters at or adjacent to the [launch],”8 the Steier court stated:
We recognize the defendant has a legitimate interest in preventing noise, wake, and wildlife problems. However, the Ordinance unreasonably singles out one type of watercraft in an effort to eliminate the deleterious effects that excessive noise and speed create. The problems of excessive noise and speed are not solely related to personal watercraft. We believe it is unreasonable to deny the use of the Batavia launch to users of personal watercraft and continue to allow all other watercraft of the same class to use the launch. Instead of singling out one type of watercraft, the defendant should enact appropriate ordinances which apply to all watercraft. The defendant has the right to regulate, but a regulation applies equally to all. Because the Ordinance singles out one type of watercraft, it is unreasonable and thus violates the permit issued by the Corps.
Steier, 283 Ill. App. 3d at 974 (citations omitted).
We find Steier unpersuasive. The issue there was whether the ban contradicted the Army Corps of Engineers’ permit or violated a state statute that prohibited “shutting] off the access to any public dock or landing thereon,”9 not whether the PWC ban was within the legislative police power. Moreover, San Juan County has determined that singling out PWC is, in fact, a logical distinction. Paragraphs 26 and 27 of the Ordinance state:
26. Existing regulations do not address the location o[r] operation of PWCs, nor do they deal with distances from machine to shoreline, speed zones, time of operation and operator safety training. The regulations also do not provide sufficient funding for enforcement, education and training. Existing laws present problems for enforcement, and create *703uncertainties with respect to the impact of the PWCs on marine sealife.
27. Although noise is regulated by RCW 88.12.085, that regulation does not address the cumulative noise of vessels operating in the same area, the annoying impact of vessels that are not destination-bound, and other noise characteristics unique to PWCs.
Ex. 249, at 11 (Ordinance No. 3-1996). These and other findings set forth in the Ordinance indicate that the County determined PWC are distinguishable from other vessels and that banning them was the most prudent policy in light of the concerns enumerated. We believe a determination such as this is best left to a legislative body. If we accept the Board’s conclusion that PWC are inherently distinguishable from other watercraft, then it logically follows that the ban is reasonable in light of the Ordinance’s purported objectives.
While replete with evidence of “displeased citizens,” the record also contains evidence of problems purportedly caused by PWC, including expert testimony regarding the harm such vessels cause to the marine environment. See, e.g., Ex. 216, at 2 (Letter from Richard Osborne, Curator of Science Services, The Whale Museum) (“The ways which PWCs appear to be different from most other vessels include: 1) speed (up to 60 mph), 2) maneuverability, which facilitates erratic, unpredictable travel paths, 3) their function, or primary use, and 4) both air and underwater noise frequencies and amplitudes. All of these variables have implications in terms of their potential for impacting our water surface-dependent wildlife . . . .”); Ex. 216, at 4 (“If PWCs were numerous in San Juan County waters they would logically present a negative impact to 49 species of seasonally resident marine birds and mammals”); CP at 440 (declaration by University of Washington Zoology professor that “San Juan County’s ban on jetskis will promote the health and success of the seabird populations in the area”); CP at 443, 444 (testimony of research wildlife biologist with National Oceanic and Atmospheric Adminis*704tration that PWC “have a high potential for creating sounds aversive to both humans and mammals” and “pose a substantial risk of noise and visual disturbance to the marine mammals which reside in San Juan County”). In sum, we find the Ordinance serves a legitimate public purpose, is supported by evidence, and is reasonable in light of the findings.
Bans of PWC have been held reasonable in other jurisdictions. In Personal Watercraft Indus. Ass’n v. Department of Commerce, 48 F.3d 540 (D.C. Cir. 1995), the court considered a National Oceanic and Atmospheric Administration (NOAA) regulation that limited the use of PWC to 14 of the 4,000-square nautical miles that compose the Monterey Bay National Marine Sanctuary. The Personal Watercraft Association had argued that treating PWC differently than all other vessels was “arbitrary and unsupported by the factual record” and, therefore, beyond the authority of NOAA, which is authorized to enact rules for the sanctuary that are “necessary and reasonable.” Personal Watercraft Indus. Ass’n, 48 F.3d at 544, 546. Nevertheless, the court concluded the regulation was “not arbitrary and capricious”:
Maybe the presence of other vessels was a cause for concern; as we shall see, NOAA thought it might be. This scarcely means that NOAA had to regulate them if it was to do anything about thrill craft. An agency does not have to “make progress on every front before it can make progress on any front.” United States v. Edge Broadcasting Co., [509] U.S. [418, 434], 113 S.Ct. 2696, 2707, 125 L.Ed.2d 345 (1993). Agencies often must contend with matters of . degree. Regulations, in other words, are not arbitrary just because they fail to regulate everything that could be thought to pose any sort of problem.
Personal Watercraft Indus. Ass’n, 48 F.3d at 544.
Although the Board’s findings here are certainly debatable, it concluded that banning PWC was necessary to further a list of public interests. Support for this conclusion was provided by the testimony of business owners, wildlife *705experts, and other individuals. “In determining whether . . . particular legislation tends to promote the welfare of the people of the State of Washington, [the court] must presume that if a conceivable set of facts exists to justify the legislation, then those facts do exist and the legislation was passed with reference to those facts.” State ex rel. Faulk v. CSG Job Ctr., 117 Wn.2d 493, 504, 816 P.2d 725 (1991) (citing State v. Conifer Enters., Inc., 82 Wn.2d 94, 97, 508 P.2d 149 (1973)).
Many times we have noted our reluctance to substitute our judgment for that of the Legislature where there is competing expert testimony in the record. See State v. Dickamore, 22 Wn. App. 851, 855, 592 P.2d 681 (1979) (“[S]o long as scientists disagree about the effect of marijuana, the legislature is free to adopt the opinions of those scientists who view marijuana as harmful. We will not substitute our judgment for that of the legislature where the statute in question bears a rational relationship to a legitimate legislative purpose.”); see also CLEAN, 130 Wn.2d at 806, 815. In light of the evidence supporting the Board’s findings, albeit contested by Respondents and their experts, and the Board’s determination that FWC possess characteristics not shared by other watercraft, we are satisfied that the Ordinance constitutes a means reasonably necessary to achieve a legitimate public purpose.
C. Local
Article XI, section 11 of the Washington Constitution is a direct delegation of the police power to cities and counties, and the power delegated is as extensive within their sphere as that possessed by the Legislature. Petstel, Inc. v. King County, 77 Wn.2d 144, 159, 459 P.2d 937 (1969). The previous discussion of police power under article XI, section 11 establishes the general scope of counties’ ability and authority to act. While a municipality cannot exercise its police power outside its boundaries, municipal legislation will not be found to violate the police power if its effect outside the county is only incidental. Petstel, 77 Wn.2d at 159. The prohibition of the use of FWC within the physical *706boundaries of San Juan County is purely local. The argument that the Ordinance has some tangential effects on interests or individuals lying geographically outside of San Juan County does not mean the Ordinance is not local, nor does the existence of the incidental effects provide the appropriate “test.” If the test required an ordinance to affect only local residents, no ordinance could be local because all laws affect, at least to some degree, individuals visiting a county or city. A ban on hunting within a city is a valid exercise of the police power. The fact that nonresidents must comply with the law does not invalidate the law or make it “not local” for purposes of the police power. The bottom line is this PWC Ordinance affects only the type of activity allowed within the county. The Ordinance does not preclude San Juan County residents from using PWC outside the County, nor does it regulate activities beyond geographical limits. As Respondents bear the burden on this issue, we reject their assertion that the subject matter of the Ordinance is not local.
Substantive Due Process
In the final prong of our analysis, we must examine whether the Ordinance violates substantive due process. We ask whether the enactment is “unduly oppressive.” This inquiry “lodges wide discretion in the court and implies a balancing of the public’s interest against those of the [person regulated].” Presbytery of Seattle v. King County, 114 Wn.2d 320, 331, 787 P.2d 907 (1990). The purpose of this analysis is to prevent excessive police power regulations that would require an individual “to shoulder an economic burden, which in justice and fairness the public should rightfully bear.” Orion Corp. v. State, 109 Wn.2d 621, 648-49, 747 P.2d 1062 (1987); see also Guimont v. Clarke, 121 Wn.2d 586, 610-11, 854 P.2d 1 (1993); Sintra, Inc. v. City of Seattle, 119 Wn.2d 1, 22, 829 P.2d 765 (1992); Robinson v. City of Seattle, 119 Wn.2d 34, 55, 830 P.2d 318 (1992). In Presbytery, we listed several nonexclusive factors relevant in determining whether an ordinance restricting property rights was unduly oppressive. These included “the *707nature of the harm sought to be avoided; the availability and effectiveness of less drastic protective measures; and the economic loss suffered by the property owner.” Presbytery, 114 Wn.2d at 331 (citing Orion Corp., 109 Wn.2d at 655 n.24).
Applying these considerations to the Ordinance at issue here, we conclude the PWC ban is not unduly oppressive. The test simply does not apply to the present case. In Sintra, the housing preservation ordinance required developers who demolished or changed the use of low-income housing to pay large fees to a city fund used to construct low-income housing. The ordinance was found to be unduly oppressive because it placed upon a discrete group of individuals and developers the responsibility of solving the society-wide problem of homelessness. This was accomplished by levying exorbitant fees, even though the developers were not responsible for the problem. Sintra, 119 Wn.2d at 22. The PWC owners are not being forced to bear a financial burden or solve a societal problem not created by PWC. To the contrary, unlike the developers in Sintra, the PWC owners are directly responsible for the problems created by the use of their machines. It defies logic to suggest an ordinance is unduly oppressive when it regulates only the activity which is directly responsible for the harm.
Vagueness
We will hold an ordinance to be unconstitutionally vague if a challenger demonstrates the ordinance either (1) fails to define the criminal offense “with sufficient definiteness that ordinary people can understand what conduct is proscribed,” or (2) does not provide “ascertainable standards of guilt to protect against arbitrary enforcement.” City of Spokane v. Douglass, 115 Wn.2d 171, 178, 795 P.2d 693 (1990). The test for whether an ordinance is sufficiently definite is “common intelligence” and does not “demand impossible standards of specificity.” Douglass, 115 Wn.2d at 179. Likewise, an ordinance is not unconsti*708tutionally vague merely because it “may require a subjective evaluation by a police officer to determine whether the enactment has been violated.” Douglass, 115 Wn.2d at 181. “[T]he enactment is unconstitutional only if it invites an inordinate amount of police discretion.” Id.
The County contends that because Respondents’ vagueness claim is a facial challenge that does not implicate their First Amendment rights, we should not even address it. “A facial vagueness challenge to an ordinance is a challenge that the terms of the ordinance ‘are so loose and obscure that they cannot be clearly applied in any context.’ ” Douglass, 115 Wn.2d at 182 n.7 (quoting Basiardanes v. Galveston, 682 F.2d 1203, 1210 (5th Cir. 1982)). In State v. Carver, 113 Wn.2d 591, 781 P.2d 1308, 789 P.2d 306 (1989), we noted that “[u]nless First Amendment freedoms are involved, this court generally will only determine whether a statute is unconstitutional as applied to the facts of the case.” Carver, 113 Wn.2d at 599 (emphasis added). Respondents counter that our use of the term “generally” indicates that we may, in certain situations, consider facial vagueness challenges outside of the First Amendment context. In a later case, however, we clearly rejected this proposition:
The rule regarding vagueness challenges is now well settled. Vagueness challenges to enactments which do not involve First Amendment rights are to be evaluated in light of the particular facts of each case. Consequently, when a challenged ordinance does not involve First Amendment interests, the ordinance is not properly evaluated for facial vagueness. Rather, the ordinance must be judged as applied. Accordingly, the ordinance is tested for unconstitutional vagueness by inspecting the actual conduct of the party who challenges the ordinance and not by examining hypothetical situations at the periphery of the ordinance’s scope.
Douglass, 115 Wn.2d at 182-83 (citations omitted). Respondents have not been cited for violating the Ordinance. Thus, theirs is a facial challenge and not appropriate for consideration.
*709Respondents nevertheless argue that “the factual record here is sufficient to allow the Court to assess how the Ordinance has affected [Respondents and others who lost the recreational, travel and commercial use of navigable public waters located within the County.” Reply Br. of Resp’ts on Cross Appeal at 5. Respondents fail to explain, however, in what manner the record before us demonstrates that the Ordinance insufficiently describes what conduct is proscribed, or fails to provide “ascertainable standards of guilt to protect against arbitrary enforcement.” Douglass, 115 Wn.2d at 178. To the contrary, the portions of the record that Respondents cite are declarations indicating that Respondents were in fact quite certain the PWC ban applied to them. See, e.g., CP at 1720 (“But for the ban, I would have used our personal watercraft . . . .”); CP at 1733 (“But for the total ban during 1996, I would have used my personal watercraft in San Juan County waters . . . .”). Respondents have not demonstrated that the Ordinance is vague as applied to them.
CONCLUSION
In sum, we conclude that the Ordinance does not conflict, for purposes of article XI, section 11 of the Washington Constitution, with RCW 88.02.020, chapter 88.12 RCW, the Marine Recreation Land Act of 1964, the Shoreline Management Act of 1971, or the public trust doctrine. The Ordinance is reasonably necessary to further the County’s legitimate public purposes and not unduly oppressive; it is a reasonable exercise of the County’s police power and not inconsistent with Respondents’ due process rights. Finally, we are unable to consider Respondents’ vagueness claim because it constitutes a facial challenge not implicating First Amendment rights.
Having concluded that the trial court erred in granting summary judgment in favor of Respondents, we must next determine whether the appropriate remedy at this stage of the proceedings is reversal or remand for trial. *710Although the rejection of one party’s cross motion for summary judgment does not compel a court to grant the opposing party’s cross motion for summary judgment, we hold that to be the appropriate remedy in this case. The County moved for summary judgment on grounds that the Ordinance was a valid exercise of its police power under article XI, section 11. Having rejected Respondents’ claim that the Ordinance is not local, reasonable, or related to a subject within the scope of the County’s police power, we hold as a matter of law that the Ordinance is a valid exercise of the County’s power enumerated in article XI, section 11 of the Washington Constitution. We will not substitute our judgment for that of a legislative body. We reverse the decision of the trial court and remand for entry of summary judgment in favor of the County on Respondents’ action for declaratory judgment. The trial court’s decision granting summary judgment in favor of the County on the Respondents’ vagueness challenge is affirmed.
Durham, C.J., and Dolliver, Smith, Guy, Madsen, and Talmadge, JJ., concur.
The Board reported receiving a petition signed by 1,479 people requesting that PWC be banned or restricted.
We recognize the Ordinance may have essentially run its course by the time this appeal is complete. If it is not reenacted, the issues before us are arguably moot. Nevertheless, we may decide a moot case if it “involves matters of continuing and substantial public interest.” Dioxin/Organochlorine Ctr. v. Pollution Control Hearings Bd., 131 Wn.2d 345, 351, 932 P.2d 158 (1997) (citing In re Detention of Swanson, 115 Wn.2d 21, 24, 793 P.2d 962, 804 P.2d 1 (1990)). This is such a case.
See RCW 36.01.050 (“All actions against any county may be commenced in the superior court of such county, or of the adjoining county . . . .”).
See CP at 488 (“Cross-Motion for Summary Judgment Re Conflict with General Laws”); CP at 534 (“Cross-Motion for Summary Judgment Re: Invalidity of Park Ban”); CP at 554 (“Cross-Motion for Summary Judgment Re: Vagueness”). Respondents’ motion regarding the park ban refers to an incident in which the County’s Parks Board Superintendent, in response to a request by two of the Respondents to use a boat launch, “unilaterally decided to prohibit commercial launching of personal watercraft from all San Juan County parks.” CP at 535. Pursuant to a stipulation by the parties, the trial court entered an order on November 6, 1996, invalidating the park ban. The County has not assigned error to that decision and, consequently, we do not address it here.
PWC are “vessels” for purposes of chapter 88.02 RCW. See RCW 88.02.010(1).
Montana, 129 Wn.2d at 592.
Homes Unlimited, Inc., 90 Wn.2d at 158.
Steier, 283 Ill. App. 3d at 973 (quoting conditions of permit issued by the Army Corps of Engineers).
Steier, 283 Ill. App. 3d at 974 (quoting 70 Ill. Comp. Stat. 1205/11-5 (West 1994)).