One of seven "Infernal" class bomb-ketchs ordered in 1758, Carcass measured 309 tons and was just 91 feet long with a beam of 28 feet. The sturdy construction necessary for bomb-ketches made her an ideal candidate to convert for Arctic exploration. Capt. Constantine Phipps commanded the 1773 expedition from the Racehorse (another converted bomb-ketch) which left the Nore in June 1773. By the end of July both ships were icebound and were fortunate that a change in the weather allowed them to escape back to Britain -- luckily preserving the young Horatio Nelson. As a fifteen-year-old midshipman on Carcass, this adventure was to be his first significant brush with danger and included his famous encounter with a polar bear. The Carcass was sold out of the service in 1784.