 A weekend cruise on a luxurious party yacht goes horribly wrong for a group of old high-school friends. They forget to let the ladder down before they jump into the ocean for a swim. The boat proves impossible to climb. They are stuck in the water many miles from shore, with baby Sara left alone on board. Sara s mother Amy must contend with her aqua-phobia as well as the group s increasing desperation, as the friends begin to turn on each other. Soon the exhaustion of keeping afloat and the struggle to get back on board begin to take a terrible toll. The happy reunion turns into a fight for survival...