I totally agree with OP. Sailing vessels should be invincible to all very low-impact collisions so they can survive being parked in a player-made dock and also not taking scrape damage while sailing slowly through a player-made canal that's lined with stone or wood pieces.

I even posted this as a suggestion in the discord channel and got a large amount of upvotes for it. But that's as good as making a wish after throwing a coin in the wishing well.