Submerged (2005)
'He found the enemy... on the wrong side.'

Here Seagal plays a mercenary (the world's best of course; expecting less from Seagal is just silly) who is freed from prison. The mercenary angle is a bit of a change of pace, but he's freed from prison in order to stop some terrorists (extra points!). Apparently these terrorists have developed a mind-control system, and then there's something in there about a submarine. At any rate you can probably consider it Under Siege in a sub. The title of the movie likewise is a change of pace since 'submerged' is an adjective, but it is pretty non-threatening, so I guess we can let that one slide. Also since the poster follows the formula perfectly, with bonus points for the blue tint, we can fully forgive the title anomaly. This was also straight to DVD.