Abstract
When using a dredge system for rock sampling from the ocean floor, it is important that the dredge system reach the desired location. However, using current systems it is difficult to know the exact position (latitude and longitude) of the dredge system. To better constrain the dredge position, we attached a small acoustic transponder to the observation wire, and attempted real-time monitoring of the dredge system's location during cruise MR08-06Leg-1b of the global ocean research vessel Mirai (R/V Mirai). Using the transponder's real-time location as displayed on the monitor screen of the acoustic navigation system on shipboard, we could precisely steer the vessel to direct the dredge along a path where rock exposures were expected by previous research. With this system we succeeded in collecting rock samples safely and reliably. Furthermore, subsequent analysis of information provided by the transponder allowed even more precise movement during towing of the dredge system.
