When the Arfon was built in 1908 in Goole for the Pattern Steam Trawling Co of Milford Haven, she was designed for trawling, not for war. A 227-ton steel ship, she was 120ft long with a 21ft beam and 11ft draught. Like her sisters, she was worked hard fishing almost every day until World War One began.The Navy requisitioned her almost at once, fitted her with a gun and put her to work even harder. She was based at Portland with several other trawlers of her type, and their main task was to sweep German mines laid by the UC-class of minelaying U-boats from the inshore shipping lanes off Dorset. Arfon swept mines for nearly three years.
On 30 April, 1917, she was directed to a suspected field of mines about 1.5 miles south of St Albans Head. Lt Edward McKeown, commanding another Portland sweeper, Vera Grace, joined the Arfon to sweep the area in which Arfon had earlier detonated a mine.
He said that the Arfon had three lookouts on her forecastle but stressed that although the sea was flat and the water clear, reflected light from the sun into which they were heading made it impossible to see much below the surface. As they reached an area marked by a lot of dead fish, there was an explosion almost under the Arfons bow, and clouds of smoke covered her.The Arfon emerged bow-down and sinking fast. Deckhand Walter Gleeson later said he thought the mine exploded under the starboard "gallows", a frame near the bow for storing spare spars and boat equipment. He saw cook James Doy run out of the galley, grab a lifebelt and jump overboard. Another man also jumped, but he was closer to the stern and the propellor caught him, killing him at once. Gleeson jumped and was dragged down by the ship, which he estimated was at an angle of 70Â°, its propeller still spinning high in the air. He was picked up by a boat from the Vera Grace, which already had leading seaman Mike Mcintyre and signalman George White aboard. They were the only survivors from the Arfon, which sank in less than a minute, taking her skipper and the other eight crewmen with her.