The Gourdou-Leseurre GL-812 HY was a 3-seat reconnaissance floatplane, built by Gourdou-Leseurre.
The prototype, called L-2, was built in 1926-27. It has a steel tube fuselage, and rectangular wooden wing. The tail was two fins, one above and one below the fuselage. The entire plane was fabric covered, except the Gnome-Rhône 9A Jupiter engine, which was left uncowled. The prototype was flown to Copenhagen, and demonstrated there to several countries.
Six prototype L-3s were constructed. They had a larger Jupiter, steel spars instead of wood, and stronger struts, allowing for shipboard catapult launching. After successfully testing the L-3, the French navy ordered 14 production GL-810 HY aircraft. The first production 810 HY flew on 23 September 1930, taking off from the Seine at Les Mureaux. In 1931, 20 GL-811 HYs were ordered, for operation from the seaplane carrier Commandant Teste and from 1933 to 1934 twenty-nine GL-812 HYs and thirteen GL-813 HYs were ordered.
While most aircraft had been retired by 1939, that August the remaining aircraft were brought together to re-equip the recently re-activated and mobilized Escadrilles 1S2 and 3S3 at Cherbourg and Berre-l'ÃÂtang, respectively and perform coastal anti-submarine patrols.