Abstract: A system for subsea operation is described, comprising a free swimming, submersible garage and docking station (10,10?), and also an associated free swimming ROV (50), where the garage and docking station (10,10?) comprises a framework (14) arranged to function as a garage (40) or docking (40?) for the free swimming ROV (50), and where the submersible garage and docking station (10,10?) comprises at least equipment in the form of several thrusters (16,18) for operation in the vertical and horizontal directions, respectively, units and a steering system for positioning in the water, and also a winch (12) connected to said ROV (50) via a cable (34) for the transfer of electricity and signals.

Abstract: A method and a device are described for survey of an ocean floor, and also cables and the like on the ocean floor in ocean areas with strong currents, as a submersible survey platform (10) is lowered from a surface vessel with the help of a winch system (12) on the vessel to a desired distance in relation to the ocean floor. The desired fixed distance from the ocean floor is controlled in real time in relation to the topography of the ocean floor at the same time as the vessel moves forward to drive the platform (10) along a desired trajectory with the help of one or more sensors that register the distance to and possibly direction towards the ocean floor and which are connected to the winch (12) via a control system (14). At the same time, sideways movements of the platform (10) caused by currents are compensated for with the help of one or more sensors that are connected to a number of thrusters (16) on the platform (10) via said control system (12).