SM U-88[Note 1] was a Type U 87 submarine built for the Imperial German Navy (Kaiserliche Marine) in World War I. U-88 was engaged in the naval warfare and took part in the First Battle of the Atlantic.

The submarine was powered by two 2,400 metric horsepower (1,800 kW; 2,400 shp) engines for use while surfaced, and two 1,200 metric horsepower (880 kW; 1,200 shp) engines for use while submerged.

[2] When submerged, she could operate for 56 nautical miles (104 km; 64 mi) at 5 knots (9.3 km/h; 5.8 mph); when surfaced, she could travel 11,380 nautical miles (21,080 km; 13,100 mi) at 8 knots (15 km/h; 9.2 mph).

U-88 was fitted with four 50 centimetres (20 in) torpedo tubes (two at the bow and two at the stern), ten to twelve torpedoes, one 10.5 cm (4.1 in) SK L/45 deck gun, and probably one 8.8 cm (3.5 in) SK L/30 deck gun.

She had a complement of thirty-six (thirty-two crew members and four officers).