Game lags and grinds to a halt sometimes in/near water, seems random, doesn't happen on land

Put the summary of the bug you're having here

What I expected to happen was...:
Normal gameplay in/near water

What actually happened was...:
Sometimes when in/near water (possibly involving shipwrecks and their chests), the game will lag and grind to a halt before crashing.  Shipwreck chests might be involved as sometimes they take some time to open...it all seems random as I don't immediately have these issues on/in the water

Steps to Reproduce:
1. Boat around an ocean for a while
2. maybe approach a shipwreck and try to explore it
3. wish I could be more specific, but usually happens in water/near shipwrecks