Hypothermia set in almost immediately, paralyzing their muscles, and preventing them from swimming back or climbing on the jet-ski.
With a few brackets it's not hard to turn that surfboard straight into a wall shelf or if you happen to really handy, replace the top of a desk with a surfboard. http://Memorialgarden.com/__media__/js/netsoltrademark.php?d=www.foryoudrive.com%2Fbbs%2Fboard.php%3Fbo_table%3Dfree%26wr_id%3D273686