Bluebird was now experiencing bouncing episodes of the starboard sponson with increasing ferocity. This was placed in a sponson on the port side aft. Fuel is stored in three tanks, one in the fuselage and one in each sponson. Like the sponson machine guns themselves, the deflector plates turned out to be useless. The other two were mounted in fixed sponson mounts. A new sponson design with two Vickers machine guns in rotating shields was produced. Canoes and kayaks sometimes feature sponson attachments as well, for stability in rough waters. For example, two seawater inlet valves were provided to each sponson. It was carried on a prominent white roundel on each sponson, underneath an infinity symbol. The sponson sides had thick plates welded on, to make them thick. The second extended from sponson to sponson and beneath which was situated the Captain's cabin. One shell damaged a sponson, started a small fire and wounded some of her crew.