CONTAINS SPOILERS AND A SENSE OF DEJA VU
Hang on a moment, haven't we been here before? Haven't we "done" CGI shark movies? We've already plodded through Shark Attack and Shark Attack 2 and Shark Attack 3 and Shark In Venice - there can't be much mileage left in indifferently animated shark attacks. Yet they still keep making them. Presumably the shark is the pre-programmed demo creature that comes bundled free with the effects software; if they want a giraffe or a komodo dragon or a coelacanth they've got to buy the upgrades. (Maybe the shockingly unconvincing octopus in Mega Shark Vs Giant Octopus was coded by a five-year-old, it certainly looks like it.)
Red Water is a wet TV-movie in which oil prospectors (in a wildlife reserve) set off an underwater explosion that releases a bull shark into the river, which promptly heads off and eats some bit-part players. Near-bankrupt charter captain and former oil worker Lou Diamond Phillips reluctantly teams up with his ex (Kristy Swanson!) and an oil company rep to trek out to the rig to monitor its impact on the local wildlife. Also upriver are some dumb crooks (including Coolio!) looking for $5m of stolen loot and generally getting in the way. And there's also the shark....
It's dull, it's desperately unoriginal, and the CGI shark effects are so lame that it might as well be a glove puppet - you really did see better effects work in Blake's Seven and the latter years of vintage Doctor Who. And it isn't even decent to look at (made in South Africa doubling for Louisiana - and why was that deemed to be cheaper than just filming it in Louisiana?). It's a thoroughly uninteresting one-star experience all the way. Watch Jaws instead. Hell, watch Jaws 4 instead.