Abstract: A float device includes a drive motor provided inside a float hull, a plunger reciprocating along with rotation of the drive motor, an internal oil reservoir for housing an hydraulic oil therein, an externally-opened cylinder attached to the float hull, a buoyant force adjustment piston reciprocating in the cylinder along with exit/entry of the hydraulic oil, and a three-way valve having a first connection port connected to the plunger, a second connection port connected to the internal oil reservoir, and a third connection per connected to the cylinder, for switching the flow between the first connection port and the second connection ports and the flow between the first connection port and the third connection port.

Abstract: The method of measuring the current below an offshore vessel by suspending a flexible member in the currents from the vessel, adding reflectors or signal generators to the flexible member, adding an adjustable weight to the bottom of the flexible member, determining the horizontal position of each reflector in comparison to the reflector above and below it, and using this information to determine the ocean currents at various levels below the vessel.

Abstract: The present invention relates to a device useful as a controllable variable speed thruster-driven oceanographic profiler for coastal waters for measuring the vertical structure of chosen properties of the oceanic water column.