What is this

ROFL i was going to show you guys the Aria 51 swimming pool on google maps but all of the sudden they dont have the images at that ZOOM any more lols .Be more obvious about thing plz

Do Aliens know how to swim?

Well, they know how to float so they probably know how to swim too.

in my opinion i agree with the idea of it being a floating sea lab/platform as its in the middle of the harbor, also there is a road built out a ways into the harbor on the bottom right where there is a boat dock so that is the main building for the structure in the middle of the harbor

also there has been talk of large fish farm structures being designed for open ocean aquafarming but they are usually under the surface not floating on it.

That sounds interesting and especially as far as the Japanese are concerned plausible.