I figured out the mysterious self destructing ship thing. Any boat sitting still unanchored takes damage. Why? I have no idea. Nothing tells you this, but I confirmed it after a weekend of underwater building using a diving attachment.
I had a cheap sloop parked out where I was building but way too deep to anchor, and after a day or two out there I noticed all of the planks were under 1000 health.
So I kind of wasted my weekend building the harbour that I don't even need. After my last schooner got thrown 100 feet in the air by some kind of magical physics fairie I figured that you just were never supposed to go in shallow water with a big boat. They have those dinghy docks, maybe you park in deep water and just row to shore right?
I guess it is just a matter of experimentation where you figure out where you can safely anchor by losing 20 hours of wood chopping and building when the dice roll doesn't go your way.
Building underwater is a major asspain. You can't see anything at night so you have to build during daylight hours, and inevitably sharks would show up and I'd waste the entire day fighting them.
Getting a large gate to snap to existing walls is next to impossible too. If I had it to do over I'd build a line of foundations on the sea floor walls up to the gate and get that placed, then do the rest. Building system is even more broken than Conan.
I'm staaaaaaaaaaaaaaack
A shark hit me so hard I almost flew into orbit:
Looking down:
Tattoos! Can't see much of them though: