Two sailing vessels were sunk off the coast of Ireland on May 21, 1917, the Norwegian bark Madura and the Russian sailing ship Lynton. Both ships had loaded cargo in the USA and were en route to Britain when the U-48 under the command of Kapitänleutnant Karl Edeling, located the Lynton and torpedoed her. All twenty-three crewmen got off the ship and into lifeboats.

According to newspaper reports the Madura arrived on the scene and was then torpedoed and sunk herself. Her crew of fifteen also all got off the ship alive, but according to the survivors and a US destroyer which happened along, the U-boat crew machine gunned the crew of the Madura while they were in the lifeboats killing two and wounding seven others.

The destroyer scared off the U-boat and did not give chase, but chose to rescue those in the water. They were landed the next day.