Who says you need a PC version of a game to get fantastic mods? Because this is the PS3 version of Grand Theft Auto V, and it's so different it may as well be an all-new game.
Made by Bushigan, it requires a modded PS3 (because you need to move some files around), but once that's done you can sink Los Santos. And drive around the state in a submarine, whispering BioShock quotes the whole time.
Here's two videos showing the mod in action. If you qualify to run it, you're going to want to bring a wetsuit.
Gta 5 - Tsunami Mod - Submarine [YouTube]