This CLEO mod makes it so that if you are on foot and you go into the water (deep enough to drown) you just respawn at the nearest shore. A few minutes (seconds) pass depending on how far you were from that respawn point. If you are in a car you still drown and die (sorry, I couldn't find a way to make it work with cars!). If you had a wanted level of 3 stars or more and you are far from the shore you respawn on a police boat and get busted.