Which Assassin's Creed game first introduced large-scale naval battles as a major gameplay feature?

Assassin's Creed III first introduced large-scale naval battles as a major gameplay feature.

The game lets players control the sailing ship Aquila in missions set along the Atlantic coast during the American Revolution. Players steer, adjust sails, fire cannons, use swivel guns, and fight enemy vessels in battles that combine navigation with tactical positioning.

Earlier Assassin's Creed games included limited water travel and maritime sequences, but Assassin's Creed III made ship handling and naval combat a substantial dedicated system. The feature was later expanded dramatically in Assassin's Creed IV: Black Flag, whose pirate setting placed ships and sea exploration at the center of the experience.

Because Black Flag is more strongly identified with naval gameplay, it is often mistakenly credited with introducing the feature. Black Flag expanded the system; Assassin's Creed III established it as a major gameplay element first.