While Shark Week seems to have become a media institution, there is more to horror-at-sea than fish with big teeth. Maritime folklore is filled with ghost ships and superstitions that are less wildlife related. These two smaller films take advantage of the situation of isolation that the ocean provides.
Below (2002)
Directed by David Twohy (Pitch Black) and co-written by Darren Aronofsky (Requiem for a Dream), Below is a ghost story in the classical sense. Set on a WWII submarine, the story is less about a ghost antagonist that needs to bested and more about the mystery surrounding the death of the sub's captain. The supernatural events occur in order to right a wrong, rather than kill everyone in sight. Twohy takes the opportunity to add some creepy visuals here and there, but resists making the climax effects-laden. The performances and writing are perhaps a little too modern, but the claustrophobic nature of submarine life is fairly well portrayed.
Triangle (2009)
(This trailer is spoilery.)
Triangle is a UK/Australian production (with no accents) that only had a DVD release in the US. Without giving away much more than the above, the plot of this movie involves a time loop (much like another semi-obscure movie, Timecrimes (2007)). Such a conceit requires very careful plotting and performances, and Triangle doesn't quite succeed in this. It cheats in an obvious way on re-watch. Given one watch though, Triangle presents some jarring moments and an ending that was truly surprising to me. Melissa George (30 Day of Night and quite a bit of television) gives a very good performance though the way the movie cheats undermines it somewhat.
Both movies are available on DVD and on Netflix instant view. Triangle is also available on Blu-ray.
