Two funny little devices that look like turtles with their feet, head and tail pulled in, float on the ocean before diving into the depths: these are the Sea Fleas.

These two exploration submersibles, also called SP-500s, roughly two by three meters and two tons, look like toys in the liquid infinity where they work.

Little sisters to the SP-350 diving saucer, the one-person Sea Fleas are extremely maneuverable and capable of reaching a depth of 500 meters. Launched in 1967, the Sea Fleas owe their concept to the technicians of the Cousteau team and their construction to those of the aeronautical factory Sud-Aviation.

The principle and equipment of the Sea Fleas are identical to those of the SP-350 but, like fighter planes, the smaller submersibles are piloted by a joystick with buttons for each finger on the grip. Once in the water, the pilots of the two subs can see each other through four Plexiglas portholes 7.5 centimeters thick; they can film each other and, most importantly, they can assist each other. The sampling arm can be used in an emergency to grab the Flea that is in trouble and raise it to the surface.

The SP-500s work as well for scientific observation as for photography and filming. The Sea Fleas were the fruit of years of work spent conceiving, constructing and perfecting the ideal tool for exploring the depths. The mini-subs enabled rapid advancement in ocean understanding, especially insofar as the great underwater ecosystems are concerned.