Abstract: A system for assessing soil properties comprises a test tool including an elongated housing including a first end and a second end opposite the first end and a sensing section. The sensing section includes a cone penetrometer test (CPT) tool protruding from the first end of the housing; a first seismic sensor housed in the housing and that senses seismic waves, one or more circuits housed in the housing and that process output of the first seismic sensor, memory housed in the housing and coupled to the one or more circuits and that stores data sensed by the sensing section, and a power source housed in the housing and that provides power for the sensing section.

Abstract: A downhole logging tool and method of use for analysing portions of a seafloor borehole in seafloor drilling operations are provided. The downhole logging tool h an underwater chassis housing a power system and sensors including at least a conductivity sensor and a magnetic susceptibility sensor which, preferably, analyse the walls of the borehole. An automatically actuated switch, preferably actuated magnetically, provides power to the sensors from the power system when the downhole logging tool is not located in a designated portion of a seafloor drilling rig (e.g. when the tool is in use traversing a borehole) and removes power when the downhole logging tool is located in the designated portion of the seafloor drilling rig (e.g. when the downhole tool is not in use).