Ocean scene was lazy
The ridiculous amount of steam swirling around in that scene should have been enough reason to just cut it from the film entirely, or at least reshoot it. It just screams "this is a heated pool in a studio, not the actual ocean". Compare with the phenomenal water scenes from Titanic. Heating the water might make the actors more comfortable, but it completely ruins the integrity of the scene.
This coupled with the shockingly bad car crash CGI really were a let down for an otherwise solid movie.