The most successful ship based floatplane of the war has to be the Walrus from cruiser HMAS CANBERRA
On the 4th. of March, 1941, KETTY BROVIG had been alongside the DKM supply ship, "COBURG," receiving fresh water. They were in the NW corner of the Indian Ocean, when discovered by the Walrus aircraft from H.M.A.S.CANBERRA. The ships had quickly separated, COBURG setting a course North, and the KETTY BROVIG headed Sth. CANBERRA went after COBURG and the Walrus, trying to slow down KETTY BROVIG dropped 4 bombs, the last two falling close by, in the ship's wake. She stopped, and then unexpectedly scuttled.
The walrus then switched her search pattern south to support CANBERRA's search. The Walrus located the Coburg was spotted by the Walrus and CANBERRA directed by radio onto the German supply ship. CANBERRA kept her distance, at about 9.5 miles, but brought the COBURG under fire. During this process COBURG was set on fire by some 8" hits into the superstructure. At that point COBURG set off scuttling charges, and subsequently sank. It was Capain Farncomb's belief, that COBURG was, in fact, a Raider, His Walrus had so described the ship on its first sighting from the air. He stayed well clear to avoid any possible use of torpedoes against his ship, a very prudent action, one would have thought.
Some 215, 8 inch shells had been used, this drew some comment after his report of proceeding arrived at Navy Office, and C in C East Indies, also put in "his two bob's worth." In general, it was thought that if Farncomb had gone closer, he would have identified COBURG much earlier, and saved a lot of expensive 8 inch shells.
At that time, Captain Burnett, was Deputy Chief of Staff; at Navy Office, he had seen, and appended his initials to the correspondence about CANBERRA and her Captain's actions, and knew what Board members had thought and said. Later he took command of HMAS SYDNEY and was faced with the same sort of situation when meeting "KORMORAN in November. SYDNEY in that action did the reverse of CANBERRA and was lost.