Typically dropped in large numbers from zeppelins, Boat Balloons consist of a standard Battle Balloon with its anti-aircraft turret switched to a dorsal deployment and a patrol boat slung beneath. The weight of the boat overcomes the buoyancy of the balloon, gently lowering the boat into the water. On touchdown, the boat's crew cuts themselves loose, and the balloon rises to an altitude where it can provide anti-aircraft cover.
Boat Balloons are an effective way of deploying a large patrol boat force without the need for a nearby base. However, the difficulty of recovering the boats by balloon has meant that it has not become a popular tactic.