The British have got the Mossie, which caused havoc in the North sea for the Kriegsmarine. With it's 57mm cannon it could do significant damage to the cargo vessels.
Best naval fighter, I'd say Zero. Although it was matched late war, and the Japanese George was better than it, the Zero lasted all war which is a great feat.
The Americans had the Hellcats and Corsairs, which could match the Japs, and did great jobs in stopping the bomber formations.
British weren't really in need of Naval aircraft as much as America or Japan. For a start the Germans didn't have any since the only Aircraft carrier they had was only 80% complete. And they had good land based fighters that could reach out from Britain. Apart from that the Seafire was a good Naval aircraft but it never really got to show it's worth against Japanese aircraft.