Abstract: A flare (1) for submarine use. The flare (1) is caused to be deployed from a submarine location where it will rise to the surface of the water because of its buoyant casing. A hydrostatic valve means (147) is provided within the casing and it opens when the flare is at or near the surface of the water to render said flare ready to project a flare composition (5) into the air. The hydrostatic valve means (147) is held inoperative by a latch mechanism (51) which is tripped as the flare is deployed from a firing tube at the submarine location. The flare composition (5) cannot be projected into the air until the flare (1) is within a range of vertical attitude determined by inclination means (13). The flare composition (5) cannot be projected into the air until the nose is above water. The flare (1) thus has a sensor (23) at its forward nose to determine that the nose is above the water.