Offshore system for delivering geotechnical tools to seafloor is described. The system includes a carrier tube that includes an upper end and a lower end, wherein the carrier tube is characterized by an outer diameter and an inner diameter and wherein the inner diameter of the carrier tube defines a hydraulic cylinder; a landing sub shaped or installed at or near the upper end of the carrier tube, wherein inner diameter of the landing sub is smaller than the inner diameter of the carrier tube; a drill bit shaped or installed at or near the lower end of the carrier tube; an extension tube extending upward from the upper end of the carrier tube; an upward seal that seals top portion of the extension tubes; a compression system for introducing compressed fluid under the upward seal; a fixed rod that runs through the hydraulic cylinder; a hydraulic piston disposed in the hydraulic cylinder, wherein the hydraulic piston is moveable along the fixed rod; one or more shear pins configured to restrict displacement of the hydraulic piston until a sufficient fluid pressure is built up; and an inner tube disposed between the carrier tube and the hydraulic piston, wherein lower portion of the inner tube includes a cone penetrometer that is ballistically inserted into the soil during downward displacement of the hydraulic piston.