Floating mooring structure comprising: a frame made up of a first plurality of tubes parallel to each other and of a second plurality of tubes parallel to each other, in which each tube in the first plurality of tubes is provided with a pair of holes (4, 4') extending longitudinally at its periphery, wherein the respective pairs of holes (4, 4') opposite each other on the tubes of the first plurality of tubes are crossed by corresponding tubes of the second plurality of tubes to form a framework; said framework further comprising first and second flotation tanks and perimeter berthing beams, characterized in that: it comprises a third plurality of tubes parallel to each other that extend in a corresponding way under the second plurality of tubes, the tubes in the second plurality of tubes and the tubes in the third plurality of tubes being parallel and being longitudinally kept separated by spacers that connect them, wherein the tubes in the third plurality of tubes pass through respective pairs of holes (5, 5') provided at the ends of a line that extends transversally the longitudinal axis of each tube in the first plurality of tubes under the horizontal plane that divides it into two semi-cylindrical portions, and wherein the pairs of holes facing each other (5, 5') on the plurality of tubes are respectively traversed by corresponding tubes of said third plurality of tubes; and in that the first flotation tanks are provided on the berthing beams (7, 7') on at " least two sides facing each other on the perimeter of the structure, and are longitudinally spaced, vertically arranged and connected to the tubes of the first plurality of tubes on each one of said at least two sides so as to seal the tubes of the first plurality of tubes; and in that the second flotation tanks are connected with the tubes in the first plurality of tubes through tubular extensions so as to to ensure the connection of ends of adjacent berthing beams (7, 7'). it comprises a third plurality of tubes parallel to each other that extend in a corresponding way under the second plurality of tubes, the tubes in the second plurality of tubes and the tubes in the third plurality of tubes being parallel and being longitudinally kept separated by spacers that connect them, wherein the tubes in the third plurality of tubes pass through respective pairs of holes (5, 5') provided at the ends of a line that extends transversally the longitudinal axis of each tube in the first plurality of tubes under the horizontal plane that divides it into two semi-cylindrical portions, and wherein the pairs of holes facing each other (5, 5') on the plurality of tubes are respectively traversed by corresponding tubes of said third plurality of tubes; and in that the first flotation tanks are provided on the berthing beams (7, 7') on at " least two sides facing each other on the perimeter of the structure, and are longitudinally spaced, vertically arranged and connected to the tubes of the first plurality of tubes on each one of said at least two sides so as to seal the tubes of the first plurality of tubes; and in that the second flotation tanks are connected with the tubes in the first plurality of tubes through tubular extensions so as to to ensure the connection of ends of adjacent berthing beams (7, 7').