It's been a terrible day for Sean. Jenna is continuing her all-out assault on him by trying to take more of his equipment (this time, the scarab and two jet skis); the beach is overrun with belligerent tourists (including a Drunk), and Congressman McKenna is demanding a meeting to discuss finances. In the midst of all this, Sean gets a call from J.D., who has just rescued an island woman who might have a back injury. J.D. is running out of energy, and needs back up in order to bring the woman in to shore without damaging her spinal chord. Not being able to leave himself, Sean sends Kekoa and Zack. Zack, as usual, is so fired up by excitement, is so in his zone because of his skills, and is so intent on saving J.D. and the victim that he ignores Kekoa's warning about riding the jet ski over the waves. He wipes out. The jet ski goes careening towards J.D. and the victim. J.D. is able to pull the victim out of harm's way, but the jet ski rams into him. He is able to muscle his way back to (thetvdb.com)