The Mediterranean. Because people have been travelling there for thousands of years, it is believed to be without secrets. And yet, far below its surface, lie vast unexplored territories, luxurious gardens worthy of the finest tropical coral reefs. These natural wonders are inaccessible to the traditional diver, in a twilight zone, between 60 and 120 m, where there’s less than 1% of sunlight. If diving at such depths is always a challenge, staying there is a fantasy, a utopia that becomes reality in Planet Mediterranean. In the tradition of Commander Cousteau and his "houses under the sea," the team of diver-photographer Laurent Ballesta is undertaking a new world-record setting mission in complete freedom and without time limit.

• Documentary