The present invention relates to a hydroelectric turbine recovery system, and in particular a system which significantly reduces the complexity of recovering a base mounted hydroelectric turbine from a deployment site on the seabed by providing a frame having an open mouth which can be advanced around the turbine before the frame is fully lowered into locking engagement with the base, thereby allowing the base, with the turbine thereon, to be recovered from the seabed.

A system for launching and recovering an underwater vehicle (18), which system comprises a crane (16) and a storage location for at least one underwater vehicle (18), wherein the crane (16) is attached to the bottom of a first container (12) and the storage location is provided in a second container (14), said first container (12) being arranged on the second container (14) during an operation of launching or an operation of recovering.

A system for launching and recovering an underwater vehicle (18), which system comprises a crane (16) and a storage location for at least one underwater vehicle (18), wherein the crane (16) is attached to the bottom of a first container (12) and the storage location is provided in a second container (14), said first container (12) being arranged on the second container (14) during an operation of launching or an operation of recovering.

A marine vessel may include a propulsion system and a rechargeable energy storage system inclusive of at least one rechargeable energy source configured to supply power to the propulsion system. The marine vessel may further include a vessel-side inductive charge component in electrical communication with the rechargeable energy storage system, and be configured to inductively couple with a platform-side inductive charge component positioned at a marine-based platform. The platform-side inductive charge component may be electrically coupled to a power generator that generates electrical power. A moveable structure (e.g., gangplank or crane) may be coupled to the marine vessel on which the vessel-side inductive charge component is positioned to enable the moveable structure to be moveably positioned to wirelessly (e.g., inductively) couple the vessel-side inductive charge component with the platform-side charge component that is positioned at the marine-based platform, thereby causing the rechargeable energy storage device to be recharged.

An ROV docked to a tether management system (TMS) is lifted outboard into water beside a vessel while deploying an umbilical that effects communication with the ROV via a tether of the TMS. After undocking the ROV to swim away from the TMS while deploying the tether, the TMS is suspended over the water while the ROV performs a subsea mission. A mobile or transportable ROV support unit can be positioned on a deck of a vessel of opportunity to facilitate deployment of the ROV, the TMS and the umbilical and to control the ROV during the mission.

An ROV docked to a tether management system (TMS) is lifted outboard into water beside a vessel while deploying an umbilical that effects communication with the ROV via a tether of the TMS. After undocking the ROV to swim away from the TMS while deploying the tether, the TMS is suspended over the water while the ROV performs a subsea mission. A mobile or transportable ROV support unit can be positioned on a deck of a vessel of opportunity to facilitate deployment of the ROV, the TMS and the umbilical and to control the ROV during the mission.

Methods for the maintenance of a marine structure having a wind turbine and at least one essentially vertical shaft are described. The methods include the use of an auxiliary floating system having: at least one floating element that remains semisubmerged throughout the process of maintaining the marine structure; at least one coupling structure that connects the system to the floating structure; and contact elements and tightening elements, wherein the contact and tightening elements are secured to the coupling structure and are intended to solidly connect the system to the shaft. Advantageously, this solid connection allows operations for the maintenance of the marine structure to be carried out in a manner that is efficient and safe for maintenance workers and for the systems involved in the operations.

A maintenance facility includes: a first barge; a first connection portion disposed on the first barge and configured to connect the first barge to a second barge mounted with a device including a maintenance target portion; and a building disposed on the first barge and including a wall portion and a roof portion. On the first barge, a temporary placing space in which the maintenance target portion can be placed is disposed between the first connection portion and the building.

A maintenance facility includes: a first barge; a first connection portion disposed on the first barge and configured to connect the first barge to a second barge mounted with a device including a maintenance target portion; and a building disposed on the first barge and including a wall portion and a roof portion. On the first barge, a temporary placing space in which the maintenance target portion can be placed is disposed between the first connection portion and the building.

A lifting element connection device for connecting a lifting element suspended from a cable to a sling element. The lifting element connection device includes a top surface having at least one angled portion which guides the lifting element towards a receiving area, and a lifting element receiving portion which holds the sling element, receives the lifting element from the receiving area, and provides a connection between the lifting element and the sling element when the lifting element is positioned in the lifting element receiving portion.