SMS Seeadler was a three-masted steel-hulled sailing ship. She was one of the last fighting sailing ships to be used in war when she served as a merchant raider with Imperial Germany in World War I. Built as the British-flagged Pass of Balmaha, she was captured by the German submarine SM U-36, and in 1916 converted to a commerce raider. As Seeadler she had a successful raiding career, capturing and sinking 15 ships in 225 days until she was wrecked, in 2 August 1917, in French Polynesia.

SM U-36 was a Type 31 U-boat in the service of the Imperial German Navy of the German Empire, employed in the commerce war in World War I.