I respectfully dissent. Contrary to the approach taken by the majority, I believe decisional law permits the parties to a sporting activity to agree to limit or reduce the possibility of injury by subjecting the activity to various restrictions and thereby impose a duty of care upon the participants. The record indicates a material dispute exists as to whether the parties made such an agreement in this case. Therefore, the majority errs in concluding that this lawsuit can be resolved by summary judgment.
Appellant’s opposition to respondent’s motion for summary judgment included excerpts of his own deposition testimony and that of respondent Reason, and the declarations of Robbi Perron, a third party witness who was a spotter on the ski boat on the day of the accident, and of Dr. Glen H. Egstrom, an expert witness in aquatic kinesiology. In summary, appellant established the following material issues of fact to support his contention that respondent Reason had a duty to limit the inherent risks incurred in tubing:
(1) Respondent Reason and Patrick Lynch were aware that appellant was physically vulnerable and had suffered a previous back injury. As he was *488getting on the inner tube and before the boat pulled away from the dock, appellant told respondent Reason to “go slow and take it easy. Kick back ’cause I don’t want to get hurt” and “ ‘[t]ake it easy. Don’t show off.’ ”
(2) After the boat began towing the inner tube it reached a speed of 30 miles per hour and appellant hand signaled to slow down just before the boat turned “pretty hard to the left and the inner tube picked up speed to about 50 to 60 miles an hour [pulling] the tube out from underneath [appellant], and [he] fell off the inner tube.”
(3) The declaration of Robbi Perron, one of the spotters on the ski boat the day of the accident, stated that “[appellant] Record specifically said to [respondent] Reason, ‘Don’t F — around, go slow and take it easy. I don’t want to get hurt.’ ” She also stated: “During Record’s ride on the tube, I noticed him struggling to hold on and attempting to signal us to slow down. At this time I turned to Reason and observed the speedometer to be pegging 30 mph at which time I tried to ad[vi]se him to slow down. At that particular time, the boat was making a sharp left turn,” and “[t]he tube ride was Record’s first and only ride on the tube and he did not fall off the tube prior to the accident.”
(4) In his declaration, Dr. Egstrom stated that he was familiar with the instruction for the specific type of tube involved in the accident here which provided: “ ‘Never exceed 25 mph when towing adults or 15 mph when towing children.’ ”
Respondent does not contradict appellant’s and Perron’s statements that Reason was told to go slow and take it easy. However, he disputes appellant’s showing as to the speed and operation of the ski boat. Respondent states that the ski boat was traveling between 15 and 25 miles per hour and that he made only a gradual to medium turn of the boat just before the accident, and, appellant did not make a hand signal to slow down.
Therefore, it is evident that there are disputed issues of material fact regarding the existence of an explicit understanding between appellant and respondent and, if so, whether respondent failed to abide by that understanding. That factual dispute must be decided before it can be concluded that appellant’s claim is barred by primary assumption of risk as a matter of law.
The majority reasons that appellant cannot establish that respondent owed any duty of care notwithstanding appellant’s showing in opposition to the summary judgment proceedings. Relying on Knight v. Jewett (1992) 3 Cal.4th 296 [11 Cal.Rptr.2d 2, 834 P.2d 696] and Ford v. Gouin (1992) 3 *489Cal.4th 339 [11 Cal.Rptr.2d 30, 834 P.2d 724, 34 A.L.R.5th 769], the majority concludes that tubing is a “sport” in which “. . . the careless conduct of others is treated as an ‘inherent risk’ of a sport, thus barring recovery by the plaintiff.” (Knight v. Jewett, supra, 3 Cal.4th at p. 316.) I submit that the majority’s analysis is too restrictive. Neither Knight v. Jewett nor Ford v. Gouin precludes participants engaging in a cooperative recreational activity from agreeing to participate in a manner to avoid or reasonably reduce the inherent risk of the activity. Such agreement would impose a duty of care defined by the tenor of their understanding.
In Knight v. Jewett, the plaintiff engaged in an informal game of touch football and was injured by another player whom she had admonished “ ‘not to play so rough or I was going to have to stop playing.’ ” (3 Cal.4th at p. 300.) The court held that the plaintiff’s claim was barred by primary assumption of risk. Its analysis turned on a consideration of various sporting activities that involve inherent risks and where such risk adds to the expected excitement of the participants. “In reaching the conclusion that a coparticipant’s duty of care should be limited . . . , the cases have explained that, in the heat of an active sporting event like baseball or football, a participant’s normal energetic conduct often includes accidentally careless behavior. The courts have concluded that vigorous participation in such sporting events likely would be chilled if legal liability were to be imposed on a participant on the basis of his or her ordinary careless conduct. The cases have recognized that, in such a sport, even when a participant’s conduct violates a rule of the game and may subject the violator to internal sanctions prescribed by the sport itself, imposition of legal liability for such conduct might well alter fundamentally the nature of the sport by deterring participants from vigorously engaging in activity that falls close to, but on the permissible side of, a prescribed rule.” (Id. at pp. 318-319, italics in original.)
Knight v. Jewett applies primary assumption of risk to vigorous, competitive sports and recreational activities engaged in by participants who wish to achieve maximum excitement and exhilaration without any regulation of their own conduct or the conduct of others. It is revealing that the court noted in Knight v. Jewett that “No rules were explicitly discussed before [the touch football] game.” (3 Cal.4th at p. 300.) That indicates that primary assumption of risk may not necessarily apply to a casual game of touch football played where there is an explicit agreement at the outset that there will be no blocking or tackling, and limiting physical contact to only touching the ball carrier. Any player failing to play according to that understanding should be viewed as violating his duty of care to other players. In other words, the court recognizes that participants may of their own volition limit, reduce, or avoid inherent risks of any sport by mutually prescribing in advance the manner in which the game is generally played.
*490The majority applies primary assumption of risk in the present matter because it sees no difference between tubing and waterskiing, drawing a parallel here with Ford v. Gouin, supra, 3 Cal.4th 339. In Ford v. Gouin, the plaintiff water-skied facing backwards and barefoot in a narrow channel. The plaintiff was a very experienced water-skier, selected the waterskiing site, wore protective equipment, and was clearly aware of the hazards of water-skiing. More importantly, there is no indication in the underlying summary judgment proceeding that there was any understanding between the plaintiff water-skier and the driver of the ski boat that the driver would do anything to limit the inherent risks of waterskiing. In other words, there were no disputed material facts and the matter was properly disposed of as primary assumption of risk as a matter of law.
Ford v. Gouin does not support the proposition that primary assumption of risk is automatically applied to individuals who participate in recreational activity involving an inherent risk, where they agree to limit or reduce the possibility of injury by agreeing to participate according to certain restrictions.
I submit that the majority has narrowly focused on the Supreme Court’s observation that sporting and recreational activities will be less amenable to summary disposition unless it is recognized that the nature of such pursuits necessarily involves inherent risks which generally eliminate any duty of care by the participants to each other save for willful and reckless conduct. In Knight v. Jewett, the court specifically makes that point: “If the application of the assumption of risk doctrine in a sports setting turned on the particular plaintiff’s subjective knowledge and awareness, summary judgment rarely would be available in such cases, for, as the present case reveals, it frequently will be easy to raise factual questions with regard to a particular plaintiff’s subjective expectations as to the existence and magnitude of the risks the plaintiff voluntarily chose to encounter. By contrast, the question of the existence and scope of a defendant’s duty of care is a legal question which depends on the nature of the sport or activity in question and on the parties’ general relationship to the activity, and is an issue to be decided by the court, rather than the jury.” (3 Cal.4th at p. 313, original and added italics.)
“[T]he parties’ general relationship to the activity” may, as here, be in dispute preventing a determination of which category of assumption of risk applies. Until there is a factual determination of whether appellant and respondent agreed to engage in tubing only under conditions to “go slow and take it easy,” appellant’s claim cannot be barred as a matter of law. Neither the trial court nor this court may ignore the evidence which supports *491appellant’s claim that respondent had a duty to limit the risks inherent in tubing by “go[ing] slow and tak[ing] it easy. Kick back, ’cause I don’t want to get hurt.”
In asserting, “As we have seen, tube riders engage in the activity of tubing in order to experience the thrill of whipping across the water at speeds which challenge their ability to stay on the tube” (maj. opn., ante, at p. 483), the majority assumes a fact which is disputed. Appellant asserted in his deposition that tubing can range from thrilling to the simple pleasure of being casually towed behind the board. (Id. at p. 482.) The record could support a reasonable inference that between themselves, appellant and respondent agreed to engage in only the latter type of casual, easy tubing.