Abstract: A hydrostatic working device for taking samples from the bottom of the sea. The working device has an outer tube (1), the cylinder tube (1), the cylinder tube with lead-through (5 and 7), and an inner tube (2), the sampling tube with a piston, whereby the space between the outer tube (1) and the inner tube (2), with the piston at the upper end, constitutes a low pressure chamber (29) filled by air under a moderate pressure, in order to keep the sampling tube (2) in an upper position until the valve opens for a working stroke. When the working device is used as a corer the sampling tube is at its lower end equipped with a catcher (4). When the tool is used as a CPT the lead-throughs (5 and 7) are replaced by (20 and 40) and the piston (3) with a piston (19), and the sampler tube (2) is replaced by a probe, and a choke valve (14) is replaced by a pressure compensated volumetric flow valve (39).

Abstract: A hydrostatic penetration device for placing on and penetration of the seabed comprises a housing (1) with a top cover (2) and a bottom cover (3), and a through-going vertical tool (4) for penetration of the seabed. The hydrostatic penetration device comprises at least one low pressure chamber (5), at least one hydraulic cylinder (6) with a vertically movable piston and piston rod (10) which can be driven to upward and downward movement by a flow of pressurised water from the surrounding water to the low pressure chamber (5), a clamping device (8) which surrounds the tool (4) and is connected to the piston rod (10), and which, during an upward and downward movement of the piston rod can be brought out of and into engagement with the tool respectively, and at least one weight (7) resting on the piston rod, which weight is vertically movable under the influence of the piston rod (10) and is arranged to transfer its weight to the clamping device (8) during a downward movement.