The paper describes the design and initial field-testing of a remotely operated submersible drill rig able to obtain continuous cores of soil and/or rock up to 6 m long. The rig mast angle is hydraulically actuated covering 90 degrees of altitude. This enables both a fully horizontal position used for deployment onto and recovery of the rig from the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133 mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters like torque, thrust, advance, injection rate and pressure are recorded. The equipment is adapted for geotechnical investigation of the renewable energy industry, as well as pipelines, cables and dredging requiring platform or near shore site investigation. The equipment is deployable from a variety of platforms and does not require a fully-fledged drill ship.