Which Assassin's Creed game is the first in the series to feature playable naval battles?

Assassin's Creed III is the first Assassin's Creed game to feature playable naval battles.

The naval missions place players aboard the Aquila, a ship commanded by Connor Kenway. They involve steering, positioning, cannon fire, boarding actions, and battles against enemy vessels in waters connected to the American Revolution.

Naval play was an important expansion of the series' formula. Earlier games included water travel and limited maritime sequences, but Assassin's Creed III made ship combat a dedicated, repeatable activity with missions and optional challenges.

Assassin's Creed IV: Black Flag later expanded the idea dramatically, making Caribbean sailing and piracy the core of its open-world structure. That popularity can lead to the mistaken belief that Black Flag introduced naval combat, although Assassin's Creed III came first.