Swimming is just like flying without fly power and water is just coloured air, unless you add bubbles, powerful streams etc.
...and oh..dear... I don't feel like fighting mini-lusca's, sharks etc. But underwater base, moon base etc would probably be a way of facing the competition. Why, I have no idea. I just load the game and autocomplete mishs every 3rd day and occationally join ITFs.
Does anyone know if any 5th can be found on the streets of the Rogue Isles? Only place I can think with Council is Sharkhead.