The Continental Shelf Division of the Marine Minerals Technology Center is proceeding with its drill systems technology program for the development of new sampling systems and the modification of existing sampling tools to meet the growing demand for more effective methods of reconnaissance exploration. Two existing drill systems, the remote placer drill and the percussion waterlift drill, have recently been modified to increase their effectiveness and versatility. The convertible drill system, a modified version of the remote placer drill, is operable in three different modes that will permit rapid reconnaissance sampling over a variety of sediment types: as a vibracore drill, as a vibralift drill, and as a remote placer drill. The percussion waterlife drill was originally used for landbased drilling operations for sampling placer mineral deposits and has been adapted for use in protected shallow-water environments. Both of these modified drill systems have been field tested, with additional modifications and testing scheduled for the near future.