Hydrostatically compensated device for ground penetration resistance measurements

A push cone device for measuring a penetration resistivity into ground, the device comprising:

• a body having an internal chamber that houses electronics;
• and
• a tip attached to the body and being configured to move relative to the body,
• wherein the tip is configured to be pressure balanced under water.

A method for measuring a penetration resistance with a push cone device, the method comprising:

• lowering the push cone device to the ocean bottom;
• self-balancing a hydrostatic water pressure acting on a tip of the push cone device so that a net pressure on the tip is negligible;
• pushing the tip into the ground;
• and
• measuring with a differential pressure sensor a pressure associated with the penetration resistance generated by the ground against the tip,
• wherein the differential pressure sensor is configured to be in fluid communication, at a first port, with an oil chamber located inside the push cone device and, at a second port, with a water passage also inside the push cone.