The Marines dispatched to investigate the downed submarine are wearing camouflage pants and grey t-shirts for the mission. No branch of the US military wears t-shirts as operational clothing.
During one of the firefights against the scorpions, one of the Marines fires his 9mm handgun more than 50 successive times without reloading. A standard clip for a 9mm, as was shown in the movie, holds fewer than half that number of rounds.
Close to ten minutes into the film it reads "Cost of California".
It should read "Coast of California".
A crewman on the bridge in the opening attack sequence is killed; just as his body starts to get dragged away, feet first, he pushes off with his arms.