I like your concept, Jesper!
The fog underwater is certainly a classic ideal for limiting view and providing a better illusion, you may also want to play around with some ambience change as well.
I think your physics idea is pretty good, though, the way it is there the objects would sort of "jiggle" at the surface. Realistically the bouyancy of the object would become less as the object approached the surface, though momentum gained from being lower at the start would allow items further down in the water to "pop up" out of the water whereas objects that started near the surface would kinda bob a little before exponentially coming to a stop.
There's a lot of math involved in water physics and quite frankly, FPSC's current scripting system isn't really up to the task.
Here's a mock-up for "Air":
:ALWAYS:localvar=1
:plrwithinzone=1:decvar=1
:plrwithinzone=0:setvar=500
:varless=0,timergreater=250:plraddhealth=-10,timerstart
The player wouldn't be able to see their air value, but while in the water, the "air local variable" will decrease and once reaching 0 or below, the player will start taking 10 damage every 1/4 second.
Any questions or concerns with Ply's Mod should be emailed to me or posted in the Mod's official thread.
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