You can use your wild shape ability to transform the ship in a limited fashion

Hammerhead 

• As a reaction you transform yourself and the ship, giving the ship a ramming ability
• Starry ram. Melee Weapon Attack: +7 to hit, range 0 ft., one object or Gargantuan creature. Hit: 10d10 bludgeoning damage. The starry ram takes 15 bludgeoning damage. Miss: The attack deals no damage, the target moves into the nearest unoccupied space that isn’t in the ship’s path, and the ship can continue moving if it has any movement left.

Inflated ooze

• As an action you transform the ship, enveloping the ship in an ooze like material
• Inflated ooze. For the next turn this ooze can catch and redirect a cannonball shot at the ship. Ranged Weapon Attack: +7 to hit, range 200/800 ft. Hit: 5d10.

Jellyfish

• As an action you transform the ship, sprouting 2 jellyfish tentacles
• Grappling arms. AC: 10, Hit points: 5, Melee Weapon Attack: +7 to hit, range 10 ft., Hit: 1d6 bludgeoning damage. The target needs to succeed on a DC 14 dex saving throw or become grappled.

Sparrow

• As an action you transform the ship, sprouting starry wings on the side of the hull.
• Starry wings. Your ship's speed is increased by 15 feet (35ft. -> 50 ft. fly speed)