HMS Pylades was a of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

.

The Catherine class was the British designation for the United States Navy's Auk class minesweeper

Auk class minesweeper

The Auk class were Allied minesweepers serving with the United States Navy and the British Royal Navy during the Second World War. In total, there were 95 Auks built.-Design and development:...

.

She was sunk on 8 July 1944 off Juno Beach

Juno Beach

Juno or Juno Beach was one of five sectors of the Allied invasion of German-occupied France in the Normandy landings on 6 June 1944, during the Second World War. The sector spanned from Saint-Aubin, a village just east of the British Gold sector, to Courseulles, just west of the British Sword sector...

 during the Normandy landings. The crew reported two explosions astern, following which the ship sank. The captain's report stated that the damage was most likely caused by two mines.

A survey of the wreck as part of Channel 4

Channel 4

Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...

's Wreck Detectives

Wreck Detectives

Wreck Detectives is the title of 2 TV documentary series from UK Channel 4 aired in 2003 and 2004 presented by Jeremy Seal, Miranda Krestovnikoff and David Manley.-Series 1 - 2003:#Alum Bay wreck, Alum Bay#Earl of Abergavenny, Weymouth Bay...

 underwater archaeological TV series indicated that the damage was actually caused by torpedo attack. Given the date of the sinking these must have been launched from German Marder

Marder (midget submarine)

The Marder was a German miniature submarine developed from the Neger. The craft was 8.3 metres long and unlike the Neger included a flooding tank in the nose allowing it to dive. Another improvement was the dome through which the pilot viewed the outside world that also served as the craft’s...

 or Neger

Neger

Neger was a German torpedo-carrying craft generally described as a human torpedo which could not submerge, but was difficult to see during night operations. The vessel was used by the Kriegsmarine between 1943 and 1945...

mini submarines, which were the only German torpedo-capable units at sea at the time of the attack.