The Perfect Corsair - Corsair Guide by Intensity

1 the HP on battleship cannon does not change in relation to the characters HP
- as explained its beneficial to use elixirs that dont heal you to your full HP if you HP washed. if you can survive the max boss hit on half hp for example you could save yourself HP thats taken away from your battleship.
to give an example: a 10000 HP corsair with battleship could use elixirs to stay above 3200 HP at zakum but not heal to full (since zakum would only deal up to 3100 damage on them). They benefit from this because taking the attack that brings the player to 1 hp and 1 mp that zakum can do would take 9999 HP away from the character and the battleship HP if they were full hp, but if the character was 5000 hp for example they would only deal 4999 damage on the player and the battleship effectively saving 5000 HP on their battleship so it lasts longer.

2. no potions dont regenerate ship HP
3. both your character and the ship take the same amount of damage