Cauldron

The Cauldron was one of the few Legendary Ships encountered by the Templar Shay Cormac in the North Atlantic during the mid-18th century. The Cauldron and her sister ship, the Pilgrim were one of the few pirate vessels after the decline of the Golden Age of Piracy. She and her sister ship were soon defeated by the Royal Navy and Cormac's ship, the Morrigan in naval combat.

Reference

 * Assassin's Creed: Rogue