Abstract: A dynamic or aerodynamic fin comprising at least two parallel arranged fin sections. At least one fin section comprises a rotational axis for installing the fin section by a rotation shaft. An end stop is provided for stopping the rotational movement of the fin section to define an extreme position. In the extreme position the fin sections provide a substantially cambered shape to the fin. The dynamic fin is improved in that it comprises a pair of coupling elements. A first fin section is coupled to a second adjacent fin section by a pair of a first and second coupling elements. The first coupling element is complementary to the second coupling element. The first coupling element is part of, preferably integral, with the first fin section and the second coupling element is part of, preferably integral, with the second fin section.

Abstract: A hydrodynamic fin, such as a keel or a rudder of a watercraft, in particular a sailing craft or surfboard, which fin comprises at least two fin sections (20,21), which are each connectable to the watercraft (31) in a manner permitting rotation, in which the fin sections are rotatable in between two extreme positions around an axis (22,23) which is substantially parallel to the longitudinal symmetrical plane of the hull, in which extreme positions the fin sections provide a mainly cambered shape to the fin, with the characteristic that the fin sections can move with a substantially constant resistance from one extreme position to the other extreme position and the hydrodynamic fin is also provided with an end-stop (26) in order to stop a rotation of the fin sections when rotating from one extreme position to the other extreme position, such that the fin sections in use take either one extreme position or the other extreme position as a result of the hydrodynamic load.

Abstract: An apparatus for laying a pipeline (2) in water, comprising a vessel (1) with devices for assembling a pipeline from pipe parts, an elongate curved guide body (4) arrange on the hull of the vessel for guiding the pipeline from the vessel into the water, and a device (3) for carrying the guide body into respectively out of the water, wherein the elongate guide body is box-like, whereby a part of the forces exerted by the pipeline is absorbed by the guide track and the load on the hull is reduced.

Abstract: An apparatus for laying a pipeline (2) in water, comprising a vessel (1) with means for assembling a pipeline from pipe parts, an elongate curved guide body (4) arranged on the hull of the vessel for guiding the pipeline from the vessel into the water, and means (3) for carrying the guide body into respectively out of the water, wherein the elongate guide body is box-like, whereby a part of the forces exerted by the pipeline is absorbed by the guide track and the load on the hull is reduced.

Abstract: A device for lifting a sea-going structure (C), such as a drilling platform consisting of a superrstructure (B) and a jacket (J), which device consists of a flotation body (1) such as a boat provided with one or more laterally slidable lifting devices (2), wherein each lifting device (2) is provided with a coupling member (5) for fixing on a part of the substructure which is arranged for movement in all directions relative to the lifting device (2), whereby the device adapts better to the swell and the relative displacement of the flotation body (1) relative to the drilling platform.

Abstract: A method for lifting a sea platform with its substructure attached from a seabed and moving that platform to a different location. Use is made of flotation bodies which are filled with water and attached to the substructure. The flotation bodies can be emptied of some water to provide greater flotation and can be rotated around a horizontal axis to facilitate movement of the entire assembly under various sea conditions.