20. Sea Beast (2009)
18. The Host (2007)
This surprise hit micro-budget pic is a terrifyingly realistic recreation of an actual event that happened when a boat mistakenly left a pair of scuba divers to fend for themselves in the middle of shark-infested waters.
14. The Reef (2011)
This tense thriller plays like an Australian Open Water, with a bigger body count and a bit more Hollywood-style action while still intimate enough to place you in the midst of the often-shocking action as a group of friends try to swim through shark-infested waters to an island after their boat capsizes.
For my money, the most memorable story in this horror anthology sequel is the simple but effective "The Raft," based on a Stephen King short story about a group of friends who become trapped on a raft in a lake by a Blob-like man-eating creature resembling an oil slick.