Thunderball

Thunderball has great underwater action scenes. SPECTRE is trying to detonate two nukes in the West, and James Bond is sent to stop them. I'd give it 7/10.

any action movie lovers that can spell scenes?

The only other extensive underwater oriented movie I can recall is The Abyss, directed by James Cameron. But there's really more deep underwater scenes with dive equipment than just scuba diving. There are some scuba diving scenes in Open Water, if you can take the harrowing tale of a couple left in the water during a scuba diving excursion. There are alot of sharks going around humans in the water scenes, too. There are other Navy SEALS oriented action movies, but the others don't have as many underwater scenes. The Rock with Sean Connery, Nicholas Cage, Ed Harris, and Michael Biehn has some brief underwater scenes when the Seal team is entering the underwater tunnels at Alcatraz, but it's only a few minutes of the film.
If you want to dig a little, there are lots of TV shows with underwater themes including the old fifties actioner "Seahunt" with Lloyd Bridges. I loved this show as a child in reruns, but it is in black and white. There aren't many shows with scuba scenes in particular, rather there are more underwater scenes.