French Submarine "U-471" (92.30m long), launched in 1930. On June 25th, 1940 it reaches Alexandria, and was captured by the british Navy. In 1943 it is used by the allies, being based in Algiers (Algeria). On December 18th, 1943 it departed from Algiers, with a crew of 74 men, bound for Marseille. As of January 13th, 1944 it is considered "as lost at sea".
Henri-Germain Delauze, CEO of the french COMEX discovered it using his "Remora" submarine.
In June 2000 Cedric Verdier, and FLorent Locatelli are the first to examine the wreck, using trimix. This is an EXTREME dive only available for the more advanced and equiped trimix divers.
It is a designated war grave.
More information on the book from JP Joncheray "80 epaves a Marseille", Editions GAP, 2004, ISBN:2 74170 290X.