Not exactly a favorite but I enjoyed "Shout at the Devil" recently....
Always "The Cruel Sea" and "Action in the North Atlantic"
Any of the "Victory at Sea" documentaries if one is feeling patriotic and adventurous.
"Abyss" is a favorite modern one. I like whoever mentioned "Alien" as well, as an outside the box example. Not noticed by most, but Ripley and the crew are merchant mariners. So are the crew in the prequel flick "Prometheus".