High Quality Content by WIKIPEDIA articles! HMS Umpire (N82) was a Royal Navy U-class submarine built at Chatham Dockyard and sunk in an accident nine days after commissioning with the loss of 22 men. The submarine was sunk whilst en-route from Chatham to join the 3rd Submarine Flotilla at Dunoon, under the command of Lieutenant Mervyn Wingfield. From Dunoon she was to carry out a single working-up patrol in the North Sea before heading to the Mediterranean. She stopped overnight at Sheerness and joined a convoy headed North. The submarine suffered engine failure with one of the two diesel engines and as a result fell behind the convoy; the propellers were driven purely by electric motors on the surface and when submerged with no mechanical linkage to the diesel engines. The convoy passed a Southbound convoy around midnight whilst about 12 nautical miles (22 km) off Blakeney, Norfolk, with the two convoys passing starboard to starboard; this was unusual since ships and convoys should pass port to port. No ships showed any lights because of the risk from German E-boats. However, an armed escort trawler, Peter Hendriks in the southbound convoy accidentally struck Umpire sinking her in 18 metres of water.