I think you underestimate how hard it is to find evidence of human settlement under sediment in the sea floor in 400 ft of water. Anything organic likely is gon

I think you underestimate how hard it is to find evidence of human settlement under sediment in the sea floor in 400 ft of water. Anything organic likely is gone, but there might be stone evidence. Unless it's something like Gobleki Tepi, it would be very hard to identify. And sites like that would be very rare, if there are any. It's worse than finding a needle in a haystack. As far as I know, little effort had been put into it.