Everytime I come back to the game, all the villagers are in the water....why is that?

Do you leave your villagers fishing when you pause and leave?

No, I've left them all researching or building and I've tried on all the settings, slow, normal and fast. Just wierd. Has it ever happened to anyone else?

How many villagers do you have? When the game is saved it doesn't save the positions of the villagers. Otherwise it would look odd if you reopened the game after some time and found all the villagers in the same places. When the game is restarted the villagers are placed more or less at random. That's why sometimes nursing mothers can be seen in the sea. It is rather unusual for all the villagers to be in the sea every time, I agree.

I got that at most times when I open my game mostly almost all in the ocean