Open Water 2: Adrift

Open WaterAdrift called Adrift in the UK, Australia, and various other countries, and called Open Waterin Germany is a 2006 Horror filmed entirely in Malta, starring Eric Dane, Susan May Pratt, Richard Speight, Jr., Niklaus Lange, Ali Hillis, and Cameron Richardson. Promotional posters claim the film is based on actual events.

A group of friends, Amy Susan May Pratt, James Richard Speight, Jr., Zach Niklaus Lange, Lauren Ali Hillis, Dan Eric Dane, and his new girlfriend Michelle Cameron Richardson go for a weekend cruise on a yacht. Amy and James also bring their infant daughter, Sarah.The friends later, jump into the water for a swim. However mistakenly, nobody thought to lower the ladder to reboard the ship, so they find themselves trapped in the water with only two masks, a dive knife, and a toy dolphin float. Minutes later, they see a boat of teenagers heading towards them. They tried to grab their attention, but the teenagers thought that they were just greeting them, before sailing off. During the struggle, they tried using a phone to call for help, only to hear the voices of some well wishers, unable to get the callers attention. Accidentally, the phone gets knocked in the water. ........

Source: Wikipedia