In the Reuther case, the Court did not grant the motion for summary judgment. Why?

Plaintiff hired defendant to take him scuba diving. On the way to the dive site, a large wave struck the boat and plaintiff was injured. Prior to the dive, plaintiff signed a waiver and release, releasing defendant for all liability. The release referred to “the potential dangers incidental to scuba diving, instruction, or snorkeling.” Defendant moved for summary judgment. Plaintiff claimed that his understanding of the agreement was that it applied only to the diving and not to the boat ride to the site. The court denied the motion for summary judgment.