Actually, I find the underwater visibility to be amusingly Disneyish - a magical undersea kingdom of bright colours and shiny light and visibility into the far distance.
Visibility of 30m underwater is something scuba divers write home about, using lots of exclamation marks - 20m is considered clear and stick a tank down there, churning up sediment with tracks and superheating water at its muzzle and you'd be lucky to see your hand in front of your face. It's rare that diving to a depth of 20m you can see the surface when you look up, whereas tearing around the Archipelago the only reason you can't see the bottom from the ground is because of the reflection of the sky.
It's dark down there too, increasing fairly quickly with depth. Those disposable underwater cameras are recommended for only down to 5 or 10 metres, not so much because of pressure considerations but just because there's not enough light for an image to capture clearly. I'd estimate that in the Archipelago a vehicle can get down to at least 30m and divers going to that depth bring a light because anything you want a good look at is going to need it.
Then there's the way colours leach with depth. It progresses along the spectrum, apparently due to Science. A spiffy fire-engine red piece of gear goes dull rusty brown pretty soon. You can notice that blues and greens are a lot more prevalent amongst diving gear than are reds and oranges, and even so such gear looks a definitely different shade underwater than it does on the surface. Those tropical fish look great in tanks, but although the undersea world can be nothing short of spectacular, it's a somewhat subtly-coloured and mysterious alien type of spectacular, rather than the bright rainbow neon living-downtown-Tokyo look of the likes of Finding Nemo.
I'm not sure what my point is. I'd imagine that adding in code to determine a vehicle's depth and shifting the visible colours along a bit as appropriate - or even just having a blanket change for being underwater - would be more work than it's worth. It's definitely WAY too bright though, with visibility far too high, and the amount of crap stirred up by doing anything should be multiplied by like a factor of ten, and take ten times as long to clear. Of course, that'd make underwater a great place to hide because it'd be nigh-on impossible to find anybody down there. But I guess that's why Bond villains like underwater as a place to hide things.
This isn't a complaint, really, more some ideas to think about or not if it's not important. Of course I can't stress enough:
DropTeam = yay.