During all these months the disguised steam trawlers were continuing their arduous work. On August 20, 1916, the _Gunner_ from Granton engaged a submarine during the afternoon, but the German subsequently dived. _Gunner_ then proceeded on a westerly course whilst she altered her disguise, and then that same evening encountered this submarine again, shelled her, but once more the enemy broke off the fight. The disguised Granton trawler _Speedwell_ was also operating in a manner similar to _Gunner_, and in the following March the trawler _Commissioner_ began her decoy work. She was a 161-ton ship armed with a 12-pounder, her method of working being as follows: Lieutenant F. W. Charles, R.N.R., was in command of the fighting portion of the crew, but her fishing skipper was otherwise in charge of the ship. _Commissioner_ proceeded to join the Granton fishing fleet, looking like any other steam trawler, and then shot her trawl and carried on like the rest of the fleet. When a submarine should appear _Commissioner_ would cut away her fishing gear and then attack the enemy. Such an occasion actually occurred the very day after she first joined the fishing fleet, but the submarine was not sunk. A similar decoy was the Granton steam trawler _Rosskeen_, which left the Firth of Forth to ‘fish’ about 20 miles east of the Longstone. Three days later she was just about to shoot her trawl when a shot came whistling over her wheelhouse, and a large submarine was then seen 8,000 yards away. After twenty minutes, during which the enemy’s shells fell uncomfortably close, _Rosskeen_ cut away her gear and ‘abandoned’ ship. The submarine then obligingly approached on the surface towards the rowing boat, and when the range was down to 1,200 yards _Rosskeen_, who was armed with a 12-pounder and 6-pounder, opened fire from the former and hit the submarine, the conning-tower being very badly damaged by the third shot. Two more shells got home, and by this time the enemy had had enough, and dived.