Looks like it is quite salvagable, plus it is in shallow fresh water. Salt water would be bad. Just pull it to shore. The wings are relatively easy to remove, even with only two people, after draining the wing fuel tanks.
Long ago my wife and I were looking at a Piper Comanche. It was not disclosed by the owner, but we eventually found out that the airplane had been completely under water during a flood for an extended period of time. The plane had a bit of a musty smell, but it flew fine.
The primary reason that we did not purchase the Comanche was because it was being sold based on a recent major overhaul on the engine. When I contacted the mechanic who had done the overhaul, he said that the mechanic had insisted that the crank not be magnafluxed. Magnafluxing the crank is a step specified in basically every manufacturer's overhaul manual. The mechanic said the owner did not want to risk having to replace or repair the crank.
But yes, it looks like that plane could be salvageable and even brought back into service.