Someone receives an artifact which is the model of a ship. He immediately is teleported on top of the ship which becomes life-size and drops in a large ocean. There are two sides in the ocean, one which represents males and one which represents females.
I read this maybe 10 years ago, but I think it was from the 1930s or so.
Since most of what I read is Asimov or Bradbury, we can probably assume that it was one of those two.
It probably wasn't either of the two because, as @M.A.Golding pointed out, their first stories came from the end of the 1930s. Good catch!