Abstract text

The present invention relates to a method of cutting (1) a small first orifice (1-1) in a wall (6) at the bottom of the sea and of opening/closing said first orifice, the method comprising anchoring a base (2) that includes a large second orifice (2-1) and a cutter device comprising: a said base, a deformable stopper (3) connected to said base and enabling said large second orifice to be opened or closed depending on the position of the stopper on the base, circular cutter means (4) secured to said base, and anchor means (5) secured to said base and suitable for anchoring said base reversibly on said wall (6). The present invention also provides a method of recovering a viscous fluid that is lighter than water, such as a polluting effluent, and that is contained in a tank of a sunken and/or damaged vessel resting on the sea bottom.