Remotely operated submarine drills are gaining acceptance as offshore geotechnical investigation tools for they provide a more convenient and often cheaper solution to geotechnical drilling vessels. The MD500 is an underwater subsea geotechnical drilling rig developed by Igeotest with the goal of retrieving high-quality physical samples of the seabed at study depths of up to 150m and with a nominal water depth of 500m. Control and automation are two key aspects with strong impact in its operational performance and ease of use, for the machine is composed of a set of remotely operated devices that must synchronize with each other: drilling rig, stabilizing legs and three manipulators for handling sampling tubes and drilling tools. These manipulators can be operated in a semi-automated fashion to help the operator focus on the drilling task. Further benefits of drilling and handling task automation include reduction of cycle time and increased repeatability, which leads to higher efficiency rates and, thus, overall reduction of operation costs. This paper presents control and operations details of the equipment as well as results yielded by several operation tests and experiments.