The Émeraude class were built as part of the French Navy's 1903 building programme to a Maugas design. They had a single hull, and a displacement of 392 tons surfaced (425 tons submerged). For surface propulsion the Émeraude class had petrol engines, and electric motors for when submerged, giving an surface endurance of 200 miles at 7.3 knots and a submerged endurance of 100 miles at 5 knots, with a maximum surface speed of 11.5 knots, and a submerged speed of 9.2 knots. Their armament was six torpedo tubes (4 forward and 2 aft). Topaze and Turquoise had a single 37mm gun, and were manned by crews of 21 men (later increased to 23 men).
damaged by Turkish gunfire and beached on 30 October 1915. Re-floated and repaired by Turkish forces; renamed Mustadieh Ombashi but never commissioned. Returned to France in 1919 and was scrapped in November 1919.