Open Water 2: Adrift

Based on a harrowing true story... A weekend cruise aboard a luxury yacht goes horribly awry for a group of old high school friends who forget to lower the ladder before they jump into the ocean for a swim. The boat proves impossible to climb, leaving them adrift, miles from shore. As the reality of the situation sinks in, 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. (official distributor synopsis)