The Defendants and Third-Party Plaintiffs, Anthony Natale and Mary-Yvon Na-tale, appeal from a judgment of the Superi- or Court, York County, which accepted the report of a referee in this controversy over a boundary. The disputed property, located on Ocean Avenue in Kennebunkport, is a gore approximately three feet by 100 feet between a lot owned by the Natales and a lot owned by the Plaintiffs, Frank Howe and Elsie Howe. The Third-Party Defendants, Dean Fales and Martha Fales, were the Natales’ predecessors in title. The Superior Court found that the Howes had established title to the disputed gore by adverse possession, that they were entitled to damages of $900 under 14 M.R.S.A. §§ 7552 and 7555 (1980), and that the Fales were not liable to the Natales under their warranty deed.
We affirm the judgment of the Superior Court.
The Howes acquired their house and lot by warranty deed in 1946. Their grantor showed them the four corners of the lot at that time, and the disputed gore was within the area indicated to them by their grantor. The owner of the adjacent lot, now owned by the Natales, disagreed orally with these boundaries, but took no further action. The Howes relied on the indicated boundaries rather than their deed, mowing to the far edge of the disputed area and later planting flowers and bushes.
*1200The Natales acquired the lot adjacent to the Howes in 1972 by warranty deed. The Natales later removed a split-rail fence which had been built by the Fales in 1968 somewhat inside what they believed to be their property line with the Howes. In 1973 or 1974 the Natale lot was surveyed, and Howe objected to the surveyor’s indications that the disputed gore was within the Natale property. In 1974 the Natales erected a wire fence along their claimed line. By 1975 part of a fence erected by the Howes on a line at right angles to the disputed boundary had been cut down, and flowers and ornamental shrubs which the Howes had planted were dug up or destroyed. The Natales put gravel over the gore and allowed automobiles to park there.
The Superior Court accepted the report of the referee who heard the parties’ testimony and reviewed their evidence. There were two reports by the referee in this case, because the first report failed to resolve the Howes’ claim under 14 M.R.S.A. § 7555 1, the Natales’ counterclaim, and the Natales’ third-party complaint against the Fales. In his first report, the referee found, and the Superior Court agreed, that the Howes had established title to the disputed property by adverse possession which ripened in 1966, while the Fales were still owners of the adjacent lot.
When we review the recommendations of a referee on appeal, our duty is simply to determine whether the findings of the referee were supported by any evidence of probative value. M.R.Civ.P. 53(e)(2). The Superior Court’s adoption of the referee’s findings of fact must be upheld if these findings are supported by credible evidence and not clearly erroneous. Clewley v. McTigue Farms, Inc., Me., 389 A.2d 849, 851 (1978).
Under Maine law “[wjhether specific possessory acts are sufficient to establish title through adverse possession can only be resolved in light of the nature of the land, the uses to which it can be put, its surroundings, and various other circumstances.” McMullen v. Dowley, Me., 418 A.2d 1147, 1154 (1980). Possession is established when the evidence shows an actual use and enjoyment of the property which is in kind and degree the same as the use and enjoyment to be expected of the average owner of such property. Id. at 1152. The land at issue here was a three foot wide strip of grass which the Howes mowed regularly after they purchased their lot in 1946 and on which the Howes later planted flowers and shrubs.
There was credible evidence to support the referee’s conclusion that this use of the property was that to be expected of the average owner of such property. The Howes’ house was very close to the disputed strip of lawn; there were few if any other imaginable uses to which it could have been put by them. Mr. Howe testified that he intended to claim the gore, whether it was included in his deed or not. We cannot say that the Superior Court’s findings on this issue were clearly erroneous.
The second report of the referee recommended, and the Superior Court awarded, treble damages of $750 under 14 M.R. S.A. § 75522 and $150 under 14 M.R.S.A. § 7555 to the Howes. In his first report, *1201also accepted by the Superior Court, the referee had recommended an award of $750 in damages under § 7552, finding that “the evidence does not support double or triple damages.” The issue of damages under § 7552 was not included in the order of reference of the Superior Court remanding the case to the referee after the first report was filed. The referee therefore was without jurisdiction to reconsider that issue. M.R.Civ.P. 53(c). The Natales challenge both awards on this appeal.
The $150 award under § 7555 must stand. It was an issue specifically included in the second order of reference. The statute simply provides treble damages for entry into a dooryard and destruction of fruit or ornamental trees or shrubs. There is probative evidence in the record to support a finding that such entry and destruction occurred.
The award under § 7552 raises an additional problem. When the Howes brought this action in 1975, the statute only provided for double damages. 14 M.R.S.A. § 7552 (1964). The statute was amended in 1977 to allow treble damages. Trial in this case took place in 1979. The law of damages is a matter of substance which is fixed when the cause of action accrues. Batchelder v. Tweedie, Me., 294 A.2d 443, 444 (1972). Therefore, the earlier language of § 7552 controls in this case. See Nyzio v. Vaillancourt, Me., 382 A.2d 856 (1978).
However, the Natales did not object to the award on this basis. Even if the language of the second report could be said to control under these circumstances, an issue which we need not decide, the Natales have waived their right to review on this issue. A reasonable view of the evidence in the record, including all justifiable inferences to be drawn therefrom, taken in the light most favorable to the Howes, supports a finding that the Natales acted willfully or knowingly as required under § 7552. Grant v. Warren Brothers Company, Me., 405 A.2d 213, 216 (1979). The amount of the award, whether single or treble damages, does not appear to be unreasonable.
The referee found, in effect, that the warranty deed from the Fales to the Na-tales neither conveyed nor purported to convey the disputed gore. The Superior Court therefore entered judgment for the Fales on the Natales’ third-party complaint for breach of warranty. The referee had reasoned that the use of the Howe property as a boundary in the Fales to Natale deed meant that the deed, executed in 1972, conveyed only to the line established by adverse possession in 1966, some three feet inside the line those parties may have contemplated at the time they were negotiating the transfer.
The relevant portion of the deed describes the property conveyed as follows:
BEGINNING at an iron pipe driven into the ground on the Easterly side of said Ocean Avenue at a point which is 59 feet Southerly of the Southwesterly corner of a parcel of land conveyed by Enid G. Ripley to Lenabel C. Fales ... thence Southerly by said Ocean Avenue 105 feet to an iron pipe driven into the ground at the Northwesterly corner of land of Elsie M. Howe; thence Easterly by said Howe land on a line which is at right angles with the last described line, (100.18) one hundred and eighteen hundredths feet to an iron pipe driven into the ground ...
The factual question posed before the referee, then, was where on the face of the earth was that “iron pipe driven into the ground at the Northwesterly corner of land of Elsie M. Howe.” In resolving that question the fact finder had assistance from the witness, Howe, who testified that the second iron pipe referred to in this section of the deed did not exist in 1946 or 1966. A pin was placed along that line by surveyors hired by Natale in 1974. Howe also testified that an iron pipe, near the line which he claims, had disappeared some time after 1946. A surveyor hired by Natale testified that a pin had been set at this location in 1963, but Fales was unable to find the pin later that year.
The referee correctly interpreted the Howe boundary line cited in the deed as a monument. Kinney v. Central Maine Pow*1202er Company, Me., 403 A.2d 346 (1979); Bryant v. Maine Central Railroad Company, 79 Me. 312, 9 A. 736 (1887). A boundary-line is a controlling monument, Liebler v. Abbott, Me., 388 A.2d 520, 521 (1978), having priority over courses and distances or quantity descriptions in a deed. Mayer v. Fuller, Me., 248 A.2d 140 (1968). “One who accepts a deed describing his land in terms of an adjoining tract is bound by the prior tract as a boundary and a monument to which any distances in the deed must yield.” Rusha v. Little, Me., 309 A.2d 867, 870 (1973).
That the boundary line was a monument is clear. The location of that boundary line is a question of fact, and this Court will therefore defer to the conclusion of the fact finder unless it is clearly erroneous. Milliken v. Buswell, Me., 313 A.2d 111, 115 (1973). This might be a case of conflicting monuments, if it were not for the fact that the critical iron pipe appears not to have been in existence in 1972, at the time of the Fales to Natale conveyance.
The reference to the second pipe in the description in the Fales’ deed is of no consequence in locating the boundaries of the Natale property because that pipe was found no longer to exist and its past location was found not to be determinable.
Both Fales and Natale testified that it was their intent that the disputed gore of land be conveyed by the deed in question. But the fact that at least one of the pipes or pins referred to by the deed did not exist when the deed was executed means that the Howe boundary line was the only existing monument at the south side of the property conveyed.
When the land is described as bounded on one side by the land of a named person, the true boundary line of such person’s land must be taken as the boundary line, and not the line as it was understood and agreed to exist at the time of the execution of the deed, if there is a variance between such two lines.
F. Clark, Law of Surveying and Boundaries § 490 (3d ed. 1959).3 The referee determined that the true boundary was located three feet north of the distance called for in the Natales’ deed because of the Howes’ adverse possession. The fact that the Howe line was the governing boundary is a question of law; the location of that line, as established by the referee, is a question of fact. McCausland v. York, 133 Me. 115, 174 A. 383 (1934). The referee’s finding must therefore stand unless clearly erroneous. Milliken v. Buswell, supra.
“If an existing line of an adjoining tract is mentioned in a deed as a boundary, it is the true line which is such boundary.” Murray v. Munsey, 120 Me. 148, 150, 113 A. 36, 37 (1921). The true line in this case is the one established by adverse possession in 1966. Occupation which amounts to disseisin can “control the express language of the deed and change the location of the true line.” Hardison v. Jordan, 141 Me. 429, 434, 44 A.2d 892, 894 (1945). Therefore, even though the Fales thought that they had conveyed title to the disputed gore by their warranty deed, they did not and could not do so. Because the Howe boundary line in the deed prevails over the course and distance calls to the south line of the property they conveyed, the deed did not truly purport to convey the disputed gore. There is thus no breach of the covenant in the warranty deed. See Rodrigue v. Morin, Me., 377 A.2d 476 (1977).
The entry, therefore, will be:
Appeal denied.
Judgment affirmed.
McKUSICK, C.J., GODFREY, J„ and DUFRESNE, A.R.J., concurring.
. § 7555 provides:
Whoever enters on any grass land, dooryard, ornamental grounds, orchard or garden and cuts down, defaces, destroys or takes therefrom, without permission of the owner, any grass, hay, fruit, vegetable or ornamental tree or shrub is liable in a civil action to the party injured in treble damages.
. This statute provided:
Whoever cuts down, destroys, injures or carries away any ornamental or fruit tree, timber, wood, underwood, stones, gravel, ore, goods or property of any kind from land not his own, without license of the owner, or injures or throws down any fences, bars or gates, or leaves such gates open, or breaks glass in any building is liable in damages to the owner in a civil action. If such an act or such acts are committed willfully or knowingly, the defendant is liable to the owner in double [treble] damages [and, in addition, for the cost of any professional services necessary for the determination of damages, for attorney’s fees, and for court costs].
14 M.R.S.A. § 7552 (1964) [word in brackets added by 1977 amendment].
. See generally 1 Patton on Titles § 153 (2d ed. 1957).