- "She's a fussock, she is. Fat and slow."
- ―Edward Thatch, on El Arca del Maestro, 1715.[src]
El Arca del Maestro (English: The Ark of the Master) was a Spanish galleon used by the French Templar Julien du Casse in late 1715. The ship was a gift from Grand Master Laureano de Torres y Ayala, to help further the Order's goals in the West Indies.
That same year, Edward Thatch and Edward Kenway planned to commandeer the galleon and station it just beyond Nassau's northern harbor, to improve the community's defenses. Kenway's Jackdaw tailed the vessel through a storm, during which the Man O' War repelled an assault from Charles Vane's Ranger.
El Arca del Maestro subsequently docked at a cove on the island of Great Inagua. Looping around the island, Kenway made his way through the jungle and assassinated du Casse aboard the galleon. Afterward, Edward claimed the cove as his own, while Thatch took the ship's cannons and beached the ship itself at Abaco Island.
- Unlike most Spanish galleons, El Arca del Maestro was painted in a similar fashion to the legendary ship El Impoluto, rather than the reddish-brown colour that was more commonly used for Men O' War.
- It is not possible to sink or disable the El Arca de Maestro during the memory Proper Defenses but it can be damaged nearly to the brink of being sunk or disabled. Even so, it will be in a proper state when Edward Kenway assassinates Julien du Casse.
- The middle mast of the El Arca del Maestro when it was beached on Abaco Island would have been the tallest viewpoint in the game but it is unreachable.