Twenty small harbour defence submarines, having a displacement of about 67 tons. They have petrol and electric motors, giving them a speed of 8 ½ knots on the surface and 5 knots when submerged. Their armament consists of one bow tube and two holders; four torpedoes are carried. Their complement is six officers and men.

Aigrette Class.

(Completed 1904.)

These two vessels are submersibles of the Laubeuf type, and were great improvements on their predecessors, the Triton Class. Their submerged displacement is 351 tons, and their dimensions 118 × 12 × 12 feet. A triple expansion steam engine of 200 H.-P. is used for surface propulsion and an electric motor of 150 H.-P. when submerged. Their speed is 10 knots and 8 ½ knots. Their maximum surface endurance is 700 miles at 8 knots, and submerged 60 miles at 6 knots. Their armament consists of one bow tube with four 18-inch torpedoes. Their complement is about fifteen officers and men.

Argonaute.

(Completed 1905.)

A submersible designed by M. Bertin (late Chief Constructor French Navy). This vessel, which was first named Omega, has a displacement of about 300 tons. She is driven by steam and electricity, and has a speed of 11 knots and 9 knots. Her armament consists of two bow tubes and two holders, with six 18-inch Whitehead torpedoes. The complement is about seventeen officers and men.

Emeraude Class.