Abstract: Buoyancy unit comprising a body (14) in which there are formed a buoyancy chamber (20) and a chamber (22) which is intended to become filled with water. According to the invention, the wall of the chamber (22) has at least two openings (24, 28), at least one opening of which comprises a nozzle (24, 28) allowing the passage of water between the chamber (22) and the outside, the nozzle being dimensioned in such a way as to appreciably slow the flow of water. The unit may form a buoyancy column intended to hold the deck of a floating rig up out of the water.

Abstract: Curvature limiter for a pipe running in a marine environment, more specifically a pipe riser (12) running between a sub-sea oil well (14) and a support (10) on the surface (16) of the sea. The curvature limiter (26) comprises at least two elements (28) which are substantially tubular and arranged around the pipe riser (12), these elements being joined together by an interconnection (30) which serves to limit the angular separation between the elements.

Abstract: Controlled-heave floating oil platform comprising a deck and a floatation assembly. According to the invention, in order to control platform response to sea movement, the floating assembly comprising a rising and falling compartment open to the sea and connected to a gas reservoir by means of a circulation pipe provided with a restriction.