I was exploring Rify north of Berezino in experimental version 0.46 (haven't been to the ship on other versions before) and it seems the ground is like walking in water for the right part of the ship where all the cabins and the bridge are.

It was sunny weather and I was dry before. While walking inside the ship (on all floors on the right side) I became damp, then wet and then completely soaked.
Later it started raining and when I went up on deck I got the message "you are getting wet" so there was no rain that came through the ship.
Must be the ground textures there.

Cheers