piece permits the barrier to extend from the wharf to the ship and comprises magnets fixed within to maintain the contact between the barrier and the ship like the part fixed on the wharf this part is provided with a floating system the part of the system that permits the canvssses to extend is preferably a kind of trellis of which all the meeting points between two slats are pivoted to allow the rotation of one against the other there are two of those trellis parallel and placed at both ends on mobile bindings these mobile bindings can move vertically along sliding rods 55 fixed on the head and the shoe 61 a device used to confine hydrocarbons in an enclosure at the time of transshipment between a fixed structure and a floating structure this device comprising extensible barrier means that can be extended from a retracted position to an extended position to cover the space between the fixed structure and the floating one the barrier means comprising a head an extensible central body and a shoe to contact the floating structure the central body may be partially immersed sliding means fixed on the fixed structure to allow the vertical movement of the head from a dry level to a partially immersed level and vice versa the barrier while in retracted position may be manipulated by the head lowered along the fixed structure to be partially immersed and then extended until a protecting shoe seals the area up to the floating structure the central body being partially immersed between the fixed structure.