Described herein are examples of stiffening shafts, which in some cases are adapted to couple to a marine vessel. An exemplary stiffening shaft can be used to extend a motor from the marine vessel or be used as a shallow water stick anchor. The exemplary stiffening shafts can include a plurality of linked vertebrae stacked to form a column and at least one inelastic tension element threaded longitudinally through the plurality of vertebrae. The shaft can have a flexible configuration when the at least one tension element is released and a stiffened linear configuration when the tension element is tensed to react to torque and bending moments. Alternatively, the stiffening shaft can be used as a shallow water stick anchor for a marine vessel by piercing the bottom of a marine environment (e.g., a sea bed, a lake bed, a river bed, etc.).

Described herein are examples of stiffening shafts, which in some cases are adapted to couple to a marine vessel. An exemplary stiffening shaft can be used to extend a motor from the marine vessel or be used as a shallow water stick anchor. The exemplary stiffening shafts can include a plurality of linked vertebrae stacked to form a column and at least one inelastic tension element threaded longitudinally through the plurality of vertebrae. The shaft can have a flexible configuration when the at least one tension element is released and a stiffened linear configuration when the tension element is tensed to react to torque and bending moments. Alternatively, the stiffening shaft can be used as a shallow water stick anchor for a marine vessel by piercing the bottom of a marine environment (e.g., a sea bed, a lake bed, a river bed, etc.).

A mooring assembly for attaching a vessel to a subsea well including a well conductor, the mooring assembly comprising: (a) a housing for the well conductor; (b) a base defining an interface for a subsea ground surface; and (c) a rotatably mounted vessel attachment point; wherein, in use, a vessel moored to the subsea well is capable of rotational movement around the subsea well.

A mooring assembly for attaching a vessel to a subsea well including a well conductor, the mooring assembly comprising: (a) a housing for the well conductor; (b) a base defining an interface for a subsea ground surface; and (c) a rotatably mounted vessel attachment point; wherein, in use, a vessel moored to the subsea well is capable of rotational movement around the subsea well.

A portable marine anchoring device maximizes holding capacity while anchored into the ground. The device is fabricated from lightweight aluminum.

The method comprises installing at least one lower section of a mooring line at the bottom of the body of water; trapping the lower section in the ground; connecting an upper unit of the floating installation to the mooring line. The lower section being constituted by a chain, the chain defining, after the connection of the upper unit, a lower end of the mooring line not provided with a mooring point pre-mounted on the mooring line, in particular an anchor or pile.

The method comprises installing at least one lower section of a mooring line at the bottom of the body of water; trapping the lower section in the ground; connecting an upper unit of the floating installation to the mooring line. The lower section being constituted by a chain, the chain defining, after the connection of the upper unit, a lower end of the mooring line not provided with a mooring point pre-mounted on the mooring line, in particular an anchor or pile.

A single-column semi-submersible platform for fixed anchoring in deep water. The semi-submersible platform comprises a lower solid ballast module, a middle seawater ballast module and a top buoyancy module. The three modules are arranged telescopically in an axial direction and can be controlled relative to each other in the axial direction such that the semi-submersible platform may float vertically and steadily in a body of water. Draught for the seawater ballast module and buoyancy module is provided by seawater ballasting. The axial position of the solid ballast module relative to the seawater ballast module is controlled by seawater being pumped in and out of a closed annulus formed between the solid ballast module and the seawater ballast module.

A single-column semi-submersible platform for fixed anchoring in deep water. The semi-submersible platform comprises a lower solid ballast module, a middle seawater ballast module and a top buoyancy module. The three modules are arranged telescopically in an axial direction and can be controlled relative to each other in the axial direction such that the semi-submersible platform may float vertically and steadily in a body of water. Draught for the seawater ballast module and buoyancy module is provided by seawater ballasting. The axial position of the solid ballast module relative to the seawater ballast module is controlled by seawater being pumped in and out of a closed annulus formed between the solid ballast module and the seawater ballast module.

The present disclosure includes recreational watercraft including a drop down boarding point. One example includes a hull, an open platform passenger deck, and a plurality of sides, continuous from the hull. The watercraft includes a panel drop down boarding point, hingedly attached horizontally to the hull, for ingress and egress of persons to the watercraft. The panel drop down boarding point includes a first surface interior to the watercraft when the panel drop down boarding point is closed, a second surface, opposite to the first surface and exterior to the watercraft when the panel drop down boarding point is closed, and an aperture formed between the first surface and the second surface and having an opening in an end surface of the panel drop down boarding point. The aperture is sized and shaped to house a retractable ladder and for the ladder to extend out through the opening.