It's a map for a the Garry's Mod gamemode Trouble in Terrorist Town. Originally I was just working on the map as one of my many whim motivated maps that never really amount to anything, but I decided to see if it would work with the gamemode. The concept was inspired a bit by the History Channel show "Life After People" when it showed what would happen to coastal cities if oceans rose. This is my attempt at making a little recreation of that scenario.
The water level is 155 Hammer inches above ground level.
There are many things sort of hard to see under the water, but here is a general overview. The playable area is a 3 block by 3 block area with the warehouse type building in the bottom middle of this screenshot being the center.

Underwater screenshots of the supermarket.


At the top of the big apartment building (white building at top right of overview screenshot).

An improvised dock (There are a few floatable boats that are steerable with the gamemode's "Magneto-stick" or the equivalent of the HL2 single-player carry with a push function).

Any comments, suggestions, criticism? Let me have it.
-Spongebob what are these visleaves doing here? You said you were gonna optimize 'em!
-But I am optimizing leaves.
-But they're still all over the map.
-Sandy I can't optimize any faster these are BIG visleaves... and they keep breaking into more leaves!