My son and I were playing and I have a map where he died. . he tried to haunt a clockwork rook and somehow he says it pushed his character off the map into the water. Once there he could never get back on land and even after disconnecting / reconnecting he was unable to exit the water tiles.
This was in a regular endless game of dont starve together. A possible solution would be to check if the character location is on a valid (non water) tile at login and if the start location is not valid, to move the character to the next nearest valid tile.
Was playing multi player game .. clockwork rook was near water / edge of map.. character haunted clockwork rook (rhino) and was pushed into the water. Character is already a ghost and cannot get out of water. but can still move to other water tiles.