Two ex-Navy divers fight both dread and fear as they are commissioned by the War Dept. to dive on the ship they served on, the USS Arizona.

The Pearl Harbor-- Arizona has been down for a very long time, so the better setting for this would be a few years after the end of WWII.

What this log fails to mention is why are they diving down there? It's not that much of a risk to go there at it's present depth.

I'm assuming this is in the past. The diver/s in the present day would be at an advanced age and probably wouldn't be diving. ?Is there a specific issue they are dealing with during the dive? Maybe they could be looking for something specific on the wreckage. What is it they dread and fear?

I would probably choose a single diver as your main character to begin with. But also you don't have a goal yet. You should read the formula page on this site and re write this logline. You need to make sure that you include a goal because at the moment you have a character and an event.