Plot: Two scuba divers are left stranded in shark-infested waters after their tour boat accidentally leaves them behind.

Main adversaries: Exposure, starvation, sharks

Why it's good: Husband-and-wife creative team Chris Kentis and Laura Lau managed to milk a surprising amount of thrills out of this nifty, ripped-from-the-headlines survival horror, thanks in large part to the gritty, "you-are-there" brand of realism employed. The nightmare scenario faced by the film's well-heeled central couple is made all the more horrifying for the banal realism with which writer/director Kentis renders their lives early on; as a result, while we may not fully identify with them on a personal level, it's hard not to put ourselves in their place as the grave nature of their plight begins to set in. - Chris Eggertsen