A flying boat is a fixed wing seaplane. This allows the plane to land on both land and water. During WW2 the flying boats were usually reserved for coast patrols and rescue missions. The advantage of being able to land on water was a large advantage meaning that it did not need an airport for it to land in.
Flying Boats in War Thunder
In War Thunder, there are several large flying boats that are available. These include the American PBY-5/PBY-5a Catalina, The German BV 238 (the largest plane in the game), the Russian Lend-Lease PBY-5a Catalina and Be-6, the British Lend-Lease Catalina Mk. IV a, the Sunderlands Mk. IIIa and V, and the Japanese F1M2, H6K4, H8K2, H8K3, A6M2-N, and N1K1 Kyofu. These aircraft were generally scout planes which accounts for many of their weaknesses. It is best to leave your front gunners to the AI as shooting manually is slow, inefficient and makes your plane locked into flying in one direction. It is also advisable to spend crew development points on the AI to help make shooting more effective.
The Flying Boats are very fragile, so try to use high-altitude bombing (on the bombers) to avoid enemy AA shells or aircraft
These Flying boats are generally very slow and are easy for fighters to catch up with and attempt to shoot down. All flying boats can land on airfields (though only the Catalina has landing gear). Flying boats will not spawn on the airfield, instead spawning near it already in the air.