From Treasure Adventure World Wiki
Boat upgrades are a specific type of gear which is applied to the player's boat, the Glooskap.
These upgrades only apply to the boat, and won't change player stats or abilities outside it.
Boat Upgrade List
|The Glooskap||Your Shrinking, Sea-Faring Vessel. Automatically deploys when needed.||NA||Receive from Mattie (Refer to Getting Started)|
|Sail||Allows the Glooskap to sail through rough waters||NA||Purchase from Vinnie in the AngelOak Island Pawn Shop for 100 coins.|
|Cannon||Press  and  to aim. Hold  to charge and release to fire||NA||Find in ???red chest in the sand behind the waterfall on Boracay Island.|
|Torpedo Upgrade||Cannon fires torpedoes that are effective underwater.||Boat Attack Power + 1||Reward for collecting and appraising 12 Numis|
|Flag||Improves the Glooskap’s aesthetics: Shows you which way the wind is blowing.||NA||Platform of the west side of Zwann Island. Purchased for 200 coins|
|Boat Armor||Increases Defense while aboard the Glooskap.||Boat Defense + 1||Receive from Mattie after stopping the Somora Island quakes.|