Surprisingly straightforward and unpretentious telling of a delicious premise -- well, delicious if one of your key cinematic experiences was Cameron's Aliens. Seriously, I can't really get enough of the "team of professionals trapped somewhere with vicious monsters" genre, so YMMV -- but after watching a half-hour of the execrable Into The Blue, a celebration of wealth and vacuousness that makes "MTV Spring Break" look like Ken Loach, I'll take this relatively sober and clamped-down affair.
And it's not without its little surprises and tensions. There's a nice moment when lead spelunker Cole Hauser peeks over a rock and into a small chamber -- I won't spoil it, but it made me laugh with surprise -- and the set-pieces (Piper Perabo's climb, the rapids, the giant lake in the pitch black cave), in and of themselves, work.
Unfortunately, Hunt doesn't seem to know how to properly pace and draw out his set-pieces. It feels like all the necessary slow parts to properly set up the action parts were edited out -- imagine Aliens without the re-grouping scene right after the transport ship crashes on the surface, or any of the lab scenes. It's particularly notable in the rapids sequence, which could've been really cool but, because we're in the dark about where it might go or what precisely the dangers are, is merely interesting. And so the film ends up a lot like those rapids: fast, brutal, but a little monotonous.