I don't really know what to say except that aside from Volcano-related crashes, almost all of my CTDs seem to occur around tidal marshes, and they're somewhat frequent in occurance; if I spend a few hours in the vicinity of one, I'm bound to have at least one. In my latest game, I got one just sailing around the perimeter of a marsh island. It doesn't look like there's anything helpful in it, but log of the latest one is attached.
Steps to Reproduce
If only I knew!
This issue has not been confirmed by a developer yet.