A modular subsea fluid storage unit comprises a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formations. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

A tow body apparatus, a method of making a modular tow body, and a method of using a tow body. The tow body comprises a nose module, a tail module, and a first payload module that may be made of plastic by three-dimensional printing. The nose module is configured to be connected to a tow cable for towing the tow body through water and comprises a nose module mating interface. The tail module comprises fins for stabilizing the tow body as the tow body is towed through water and a tail module mating interface. The first payload module comprises an interior configured to hold a payload, a first mating interface configured to be attached alternatively to the nose module mating interface or to a second payload module, and a second mating interface configured to be attached alternatively to the tail module mating interface or to the second payload module.

Systems and methods for launching and retrieving payloads in aquatic environments employ a platform that is both floatable and submersible at the discretion of and/or under the control of a user, on which submersible objects to be launched, delivered to a subsea location and/or retrieved (the payload) may be located. The submergible platform has a plurality of sealed and/or sealable buoyancy chambers and at least one low pressure gas storage tank having associated fixtures and valves providing introduction of gas to the buoyancy chambers. One or more buoyant elements may be coupled to the submersible platform to support the platform in a submerged condition. A payload docking system providing secure docking of a payload on the platform deck is also disclosed.

A tow body apparatus, a method of making a modular tow body, and a method of using a tow body. The tow body comprises a nose module, a tail module, and a first payload module that may be made of plastic by three-dimensional printing. The nose module is configured to be connected to a tow cable for towing the tow body through water and comprises a nose module mating interface. The tail module comprises fins for stabilizing the tow body as the tow body is towed through water and a tail module mating interface. The first payload module comprises an interior configured to hold a payload, a first mating interface configured to be attached alternatively to the nose module mating interface or to a second payload module, and a second mating interface configured to be attached alternatively to the tail module mating interface or to the second payload module.

A subsea storage unit includes a pressure hull having a cargo hold configured for storing cargo. The pressure hull has a movable hatch, providing access to the cargo hold; and a base configured for supporting the storage unit on a seabed. The unit also includes a suspension, whereby the storage unit can be lifted and lowered in a body of water, and a ballast. A seabed facility can be configured for receiving and accommodating at least one subsea storage unit.

A method of deploying autonomous underwater vehicles (AUVs), the method comprising loading the AUVs into a deployment device; submerging the deployment device containing the AUVs after the AUVs have been loaded into the deployment device; towing the submerged deployment device containing the AUVs with a surface vessel; deploying the AUVs from the submerged deployment device as it is towed by the surface vessel; and operating a thruster of each AUV after it has been deployed so that it moves away from the submerged deployment device. A method of retrieving autonomous underwater vehicles (AUVs) is also disclosed, the method comprising towing a submerged retrieval device with a surface vessel; loading the AUVs into the submerged retrieval device as it is towed by the surface vessel; and after the AUVs have been loaded into the submerged retrieval device, lifting the submerged retrieval device containing the AUVs out of the water and onto the surface vessel.

Disclosed is a subsea storage unit (15; 15; 15) including a pressure hull (1) having a cargo hold (5) configured for storing cargo (3, 7) and a base (2; 8) configured for supporting the storage unit on a seabed (B). The pressure hull has a movable hatch (4), providing access to the cargo hold. The subsea storage unit also includes suspension means (11a,b, 35), wherein the subsea storage unit may be lifted and lowered in a body of water, and ballasting means. A seabed facility (30), configured for receiving and accommodating at least one subsea storage unit, is also provided.

A method of transporting a rigid tie-in connection across a body of water for installation underwater is disclosed. The method includes the step of supporting the tie-in connection in the water by buoyancy acting on a frame that supports the tie-in connection until installation. The buoyancy-supported frame is lowered and the tie-in connection into a sub-surface transit configuration. The method further includes in the transit configuration, towing the buoyancy-supported frame and the tie-in connection behind a towing vessel toward an installation site. Also disclosed is a system for implementing the method. The system includes a towable frame arranged to support the tie-in connection until installation and an external buoyancy attached to the frame by an extensible suspension link arranged to suspend the frame from the buoyancy in water in use. The link is extensible to lower the frame from a raised surface-tow configuration into a lowered sub-surface transit configuration.

This disclosure provides wave-powered vessels equipped for fish stock management. The vessels have observational sensors for monitoring fish, a positional sensor to determine the geographical location of the vessel, and a transmitter for sending data to a central control unit. The observational sensors may be deployed on a tow body pulled behind the vessel, or the tow body may relay information from sensors located on a separate unit on the bottom or at a defined depth. The control unit communicates with each of the monitor vessels to direct navigation and obtain data from the sensors. Substance distribution vessels in the fleet are equipped to distribute fish food in target area for the purpose of fish farming.

A mechanical attachment mechanism includes a clamp and a receptacle. The clamp includes a trigger arm and catchment fingers biased to pivot toward the trigger arm. The receptacle includes an aligner and curved grooves. The curved grooves each have open exterior and closed interior ends. The trigger arm of the clamp is biased from a triggered position toward secured and extended positions. The extended position is for the trigger arm beginning and ending contact between the trigger arm and the aligner. The extended position is also for the trigger arm capturing the catchment fingers of the clamp from the open exterior end of the curved grooves of the receptacle. The triggered position is for the trigger arm releasing the catchment fingers into the curved grooves. The secured position is for securing the clamp and the receptacle together with the catchment fingers engaging the closed interior end of the curved grooves.