A person generally owes a duty of due care not to cause an unreasonable risk of harm to others. (Civ. Code, § 1714; Kahn v. East Side Union High School Dist. (2003) 31 Cal.4th 990, 1003 [4 Cal.Rptr.3d 103, 75 P.3d 30] (Kahn).) One of the exceptions to this general rule is the doctrine of primary assumption of the risk. Under this doctrine, “sports participants have a limited duty of care to their coparticipants, breached only if they intentionally injure them or ‘engage[] in conduct that is so reckless as to be totally outside the range of the ordinary activity involved in the sport.’ ” (Shin v. Ahn (2007) 42 Cal.4th 482, 486 [64 Cal.Rptr.3d 803, 165 P.3d 581], quoting Knight v. Jewett (1992) 3 Cal.4th 296, 320 [11 Cal.Rptr.2d 2, 834 P.2d 696] (Knight).) In determining whether the defendant owed a duty to the plaintiff, courts do not focus on “the reasonableness or unreasonableness of the plaintiff’s conduct, but rather on the nature of the activity or sport in which the defendant is engaged and the relationship of the *895defendant and the plaintiff to that activity or sport.” (Knight, at p. 309.) This doctrine applies not only to participants in competitive events, but also to those who “engaged in noncompetitive but active sports activity.” (Ford v. Gouin (1992) 3 Cal.4th 339, 345 [11 Cal.Rptr.2d 30, 834 P.2d 724] (Ford).) “[A]n activity falls within the meaning of ‘sport’ if the activity is done for enjoyment or thrill, requires physical exertion as well as elements of skill, and involves a challenge containing a potential risk of injury.” (Record v. Reason (1999) 73 Cal.App.4th 472, 482 [86 Cal.Rptr.2d 547].) Whether the defendant owes a duty to the plaintiff is a question of law. (Kahn, supra, 31 Cal.4th at p. 1004.)
In Whelihan v. Espinoza (2003) 110 Cal.App.4th 1566 [2 Cal.Rptr.3d 883] (Whelihan), the record established that the “defendant drove his jet ski at ‘a relatively high rate of speed’ while making turns and maneuvers in ‘relatively close proximity’ to [the] plaintiff’s jet ski. The jet skis collided when [the] plaintiff made a left turn in front of [the] defendant.” (Id. at p. 1570.) The reviewing court reasoned that “jet skiing is an active sport involving physical skill and challenges that pose a significant risk of injury, particularly when it is done—as it often is—together with other jet skiers in order to add to the exhilaration of the sport by racing, jumping the wakes of the other jet skis or nearby boats, or in other respects making the sporting activity more challenging and entertaining. [Citations.]” (Id. at p. 1573, fn. omitted.) Thus, the Whelihan court held that the primary assumption of the risk doctrine barred the plaintiff’s claims. (Ibid.)
The court in Peart v. Ferro (2004) 119 Cal.App.4th 60 [13 Cal.Rptr.3d 885] (Peart) reached the same conclusion. In Peart, the plaintiff was operating a two-seater Sea-Doo or personal watercraft while one of the defendants was operating a three-seater Sea-Doo. (Id. at pp. 65, 67, fn. 2.) As the plaintiff drove his Sea-Doo around the lake, he accelerated, made turns, and cut back and forth across the defendant’s wake. The defendant was traveling at 30 miles per hour when the plaintiff accelerated to 45 to 50 miles per hour. The plaintiff then turned into the defendant’s path, and the vehicles collided. (Id. at pp. 66-67.) The Peart court held that “there is no legally material difference between the jet skis at issue in Whelihan and the Sea-Doos used in this case” and agreed with the Whelihan court’s “analysis of jet siding as ‘an active sport involving physical skill and challenges that pose a significant risk of injury to participants in the sport,’ a description which applies equally to the recreational activity of riding a Sea-Doo.” (Id. at p. 74.)
Under Whelihan and Peart, Cu Van Nguyen (Cu Van) and Anthony Nguyen (Anthony), as drivers of personal watercraft on a lake, were engaging in a sport that was subject to the doctrine of assumption of the risk. Cu Van also established that his conduct was within the range of ordinary activity *896involved in the use of a personal watercraft, because a collision with another participant is an inherent risk of the sport. In my view, Rachael Truong (Rachael) was also a participant in this sport. The passenger of a personal watercraft is engaged in an activity that is done for enjoyment or thrill. A personal watercraft has no hull or cabin, thus bringing the passenger into close contact with the elements. The passenger also experiences the effects of high speed and quick turns, and will get some lift off the seat when the vessel encounters a wave. (Ford v. Polaris Industries, Inc. (2006) 139 Cal.App.4th 755, 760 [43 Cal.Rptr.3d 215].) Physical exertion and skill is also required of a passenger. Though the driver controls the speed and direction of the personal watercraft, the passenger must maintain his or her balance by holding on to the driver or handles on the vessel. In the event that the personal watercraft overturns or the passenger falls, the passenger must be able to stay afloat or swim to safety. The potential risk of injury also applies to the passenger. Thus, given the nature of the activity and that Cu Van, Anthony, and Rachael were coparticipants in the use of personal watercraft on a lake, Cu Van had no duty to Rachael. Accordingly, the trial court correctly found that the doctrine of primary assumption of the risk barred plaintiffs’ negligence claim against Cu Van.1
The case of Shannon v. Rhodes (2001) 92 Cal.App.4th 792 [112 Cal.Rptr.2d 217] (Shannon) is factually distinguishable from the present case. In Shannon, when the defendant accelerated his boat, the plaintiff, who was a passenger, fell out of the boat and was severely injured. In contrast to riding in a boat, riding on a personal watercraft requires physical exertion and skill, and the potential risk of injury is significantly greater.
Plaintiffs note that Anthony and Rachael were not traveling at high speeds, but merely taking a casual ride around the lake. Thus, they argue that courts should distinguish between “casual” and “extreme” sporting activities in applying the primary assumption of the risk doctrine. However, this distinction would be contrary to Knight and Ford. In Knight, the participants engaged in an “informal game of touch football . . . using a ‘peewee’ football” in a dirt lot. (Knight, supra, 3 Cal.4th at p. 300.) The Knight court did not focus on the level at which the sport is played, but on the nature of the risks Inherent in the sport or activity. Similarly, in Ford, the court rejected the plaintiff’s argument that this “limited duty should not apply in the context of a ‘cooperative’ sport such as waterskiing.” (Ford, supra, 3 Cal.4th at p. 345.) The court reasoned that the rationale of the authorities cited in Knight applied equally “to an active sport such as waterskiing even when it is engaged in on a noncompetitive basis.” {Ibid.) Thus, there is no merit to plaintiffs’ argument.
*897Plaintiffs also contend that the trial court erred in granting summary judgment in favor of Chuong Nguyen (Chuong). Plaintiffs alleged that Chuong negligently entrusted the personal watercraft to Cu Van.
“Liability for negligent entrustment amounts to a determination whether a duty exists to anticipate and guard against the negligence of others. [Citation.]” (Lindstrom v. Hertz Corp. (2000) 81 Cal.App.4th 644, 648 [96 Cal.Rptr.2d 874].) Since Cu Van had no duty to Rachael, thus precluding a negligence claim against him, Chuong could not be negligent in entrusting the personal watercraft to Cu Van. Accordingly, the trial court properly granted summary judgment in favor of Chuong.
The trial court held that plaintiffs’ negligence per se causes of action lacked merit. Since plaintiffs have not presented argument on this issue, they have waived any claim of error.