A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames provides a space under the frame and in between the barges that enables a package to be lifted and/or a marine vessel to be positioned in between the barges and under the frames. In this fashion, an object that has been salvaged from the seabed can be placed upon the marine vessel that is positioned in between the barges and under the frames.

A motion compensating crane for use on an offshore vessel having a hull with a design waterline, wherein the crane includes a revolving superstructure, a main boom mounted to the revolving superstructure and pivotally connected at an inner end thereof about a substantially horizontal boom pivot axis to the revolving superstructure, the main boom having a tip end remote from the inner end, a main boom luffing assembly adapted to set an angle of the main boom relative to the superstructure within a main boom working angle range, a rigid jib frame pivotally connected to the tip end of the main boom about a substantially horizontal jib frame pivot axis, and a level setting assembly adapted to set the rigid jib frame in a levelled position whilst the main boom has an angle within the main boom working angle range. The rigid jib frame is provided with a set of parallel X-direction tracks which are substantially horizontal in the levelled position of the rigid jib frame. The crane further has a mobile carrier supported by the X-direction tracks and movable by a motor powered X-motion displacement actuator assembly. The mobile carrier is provided with one or multiple parallel Y-direction tracks and a mobile jib hoist cable suspension member is supported by the one or more Y-direction tracks and movable relative thereto.

A motion compensating crane for use on an offshore vessel having a hull with a design waterline, wherein the crane includes a revolving superstructure, a main boom mounted to the revolving superstructure and pivotally connected at an inner end thereof about a substantially horizontal boom pivot axis to the revolving superstructure, the main boom having a tip end remote from the inner end, a main boom luffing assembly adapted to set an angle of the main boom relative to the superstructure within a main boom working angle range, a rigid jib frame pivotally connected to the tip end of the main boom about a substantially horizontal jib frame pivot axis, and a level setting assembly adapted to set the rigid jib frame in a levelled position whilst the main boom has an angle within the main boom working angle range. The rigid jib frame is provided with a set of parallel X-direction tracks which are substantially horizontal in the levelled position of the rigid jib frame. The crane further has a mobile carrier supported by the X-direction tracks and movable by a motor powered X-motion displacement actuator assembly. The mobile carrier is provided with one or multiple parallel Y-direction tracks and a mobile jib hoist cable suspension member is supported by the one or more Y-direction tracks and movable relative thereto.

Disclosed is a floating structure for an autonomous watercraft with a keel deployed and recovered on a vessel. The longitudinally elongate structure includes a floating port-side and starboard lateral edges and a submersible bottom submerged when the structure is in the water, the lateral edges and the bottom defining an interior space at least partly submerged when the floating structure is in the water, the lateral edges defining a prow at the front and, at the rear, an opening towards the rear of the floating structure, which opening is downwardly limited by the submersible bottom with at least one longitudinally elongate slot open towards the rear for the passage of the keel, and the floating structure is configured in order that at least the front portion of the autonomous watercraft including the keel can engage by floating inside the interior space, with the keel engaging in the slot.

Virtual anchor features for a navigation/autopilot system for use on a marine vessel are provided herein. An example apparatus associated with a marine vessel includes a processor and memory including computer program code, the memory and the computer program code configured to, with the processor, cause the apparatus to receive user input indicating at least a first geographic location and a desired offset distance; determine a current geographic location of at least one of the marine vessel or the apparatus; determine if the current geographic location is within a distance threshold of the desired offset distance from the first geographic location; and cause, in an instance in which the current geographic location is not within the distance threshold, one or more motors of the marine vessel to operate to cause the marine vessel to move to a new geographic location accordingly. A desired orbit pattern may also be employed.

Virtual anchor features for a navigation/autopilot system for use on a marine vessel are provided herein. An example apparatus associated with a marine vessel includes a processor and memory including computer program code, the memory and the computer program code configured to, with the processor, cause the apparatus to receive user input indicating at least a first geographic location and a desired offset distance; determine a current geographic location of at least one of the marine vessel or the apparatus; determine if the current geographic location is within a distance threshold of the desired offset distance from the first geographic location; and cause, in an instance in which the current geographic location is not within the distance threshold, one or more motors of the marine vessel to operate to cause the marine vessel to move to a new geographic location accordingly. A desired orbit pattern may also be employed.

There is disclosed a retrieval system for retrieving a vessel from water to a deck of a recovery vessel, comprising: a lifting device mounted on the deck of the recovery vessel, the device comprising a substantially vertically extending structure and a lifting hook mounted to said substantially vertically extending structure so as to be raised and lowered therefrom by way of a first winch; a connection lead having a free end configured to detachably connect to a connection link of the vessel to be retrieved from the water an opposing end of the connection lead being located on the recovery vessel; a capture member mounted with respect to the lifting hook to capture the connection link of the vessel when the free end of the connection lead is raised towards the lifting hook; and a control member mounted with respect to the lifting hook of the lifting device and configured to receive at least a portion of the connection lead so as to direct the connection link to the capture member to be captured thereby as the free end of the connection lead is raised towards the lifting hook; wherein upon capture of the connection link by the capture member the winch is operated to facilitate lifting of the vessel from the water to the deck of the recovery vessel.

There is disclosed a retrieval system for retrieving a vessel from water to a deck of a recovery vessel, comprising: a lifting device mounted on the deck of the recovery vessel, the device comprising a substantially vertically extending structure and a lifting hook mounted to said substantially vertically extending structure so as to be raised and lowered therefrom by way of a first winch; a connection lead having a free end configured to detachably connect to a connection link of the vessel to be retrieved from the water an opposing end of the connection lead being located on the recovery vessel; a capture member mounted with respect to the lifting hook to capture the connection link of the vessel when the free end of the connection lead is raised towards the lifting hook; and a control member mounted with respect to the lifting hook of the lifting device and configured to receive at least a portion of the connection lead so as to direct the connection link to the capture member to be captured thereby as the free end of the connection lead is raised towards the lifting hook; wherein upon capture of the connection link by the capture member the winch is operated to facilitate lifting of the vessel from the water to the deck of the recovery vessel.

A compact and simplified heave compensation system for reducing the effect of waves or wavelike movements on a lifting device. The system can have active and passive heave compensation components. An overload protection to protect lifting equipment can also be implemented. The system enables accurate load and displacement calculations, as well as simplifying the control schemes utilized for lifting devices.

A compact and simplified heave compensation system for reducing the effect of waves or wavelike movements on a lifting device. The system can have active and passive heave compensation components. An overload protection to protect lifting equipment can also be implemented. The system enables accurate load and displacement calculations, as well as simplifying the control schemes utilized for lifting devices.