According to one or more embodiments disclosed herein is a method of transporting equipment between sea-surface and seafloor by providing a structure with a subsea equipment package mounted thereon. The structure is used for installation and recovery in a subsea environment by changing the buoyancy of the structure or ballasting the structure to effect a controlled sinking motion.

The present invention provides a device useful for transporting and/or handling equipment in an underwater environment for performing work, the device comprising at least the following components: a floating hydraulic unit (1) comprising a first enclosure (1a), preferably with a cylindrical wall, containing an electrical pump unit (6), a battery (8) suitable for electrically powering the pump unit, and a fluid tank (7), preferably containing oil, said first enclosure (1a) being suitable for being made submersible by first ballast (16); at least one hydraulic tool (3) connected or suitable for being connected to at least one hydraulic coupling (11, 12) of said hydraulic unit via at least one flexible hose (30); at least one independent float (4), preferably having a cylindrical wall, connected or suitable for being connected to said hydraulic tool (3) via a sling (5) of adjustable length, said float (4) being suitable for being made submersible by second ballast (43); and a wired remote control (2) for switching on or stopping the pump unit (6), said wired remote control comprising a handle (22) fitted with an electrical contactor (2a) at a first end of an electric wire (20), the second end of the electric wire (20) being connected or suitable for being connected at least to said pump unit (6).

The present invention provides a device useful for transporting and/or handling equipment in an underwater environment for performing work, the device comprising at least the following components: a floating hydraulic unit (1) comprising a first enclosure (1a), preferably with a cylindrical wall, containing an electrical pump unit (6), a battery (8) suitable for electrically powering the pump unit, and a fluid tank (7), preferably containing oil, said first enclosure (1a) being suitable for being made submersible by first ballast (16); at least one hydraulic tool (3) connected or suitable for being connected to at least one hydraulic coupling (11, 12) of said hydraulic unit via at least one flexible hose (30); at least one independent float (4), preferably having a cylindrical wall, connected or suitable for being connected to said hydraulic tool (3) via a sling (5) of adjustable length, said float (4) being suitable for being made submersible by second ballast (43); and a wired remote control (2) for switching on or stopping the pump unit (6), said wired remote control comprising a handle (22) fitted with an electrical contactor (2a) at a first end of an electric wire (20), the second end of the electric wire (20) being connected or suitable for being connected at least to said pump unit (6).