sometimes boat health doesnt make sense. i once crashed into a mistlands rock at full speed with a full repaired longship. the ship got destroyed INSTANTLY by the collision. thankfully water was very shallow so i could recover the precious nails with your lord and savoir the hoe. thankfully it was on a exploration trip with no metals in the boat yet.
this never happed again. despite tryingt it out and hitting the same rock with full speed again. my guess is that boat health is sometimes not saved correctly by the game for some reason. or dmg caculations go haywire once in a blue boon during collisions.

serpents arent a threat anymore now so they rarely hit my boat and when i spot one all i can see is MEAT to make more stew. let one bite just now after seeing this thread. it did like 50+ dmg to the longship.

so you probaly had a dmg caculation go haywire aswell?

or its a mod issue if you use any.

big waves can also dmg the boat and that dmg is often not noticed.