Development of a New Spilled Oil Tracking Autonomous Buoy

AbstractOil spills cause tremendous damage to the ocean environment, which the unfettered drifting of spilled oil exacerbates. If the exact location of drifting oil could be identified in real time beginning when the oil spill first occured, then drifting oil could be recovered at sea before washing ashore. In addition, if meteorological and oceanographic data around the drifting oil could be obtained, the accuracy of an oil drifting simulation would be enhanced by data assimilation, and oil recovery machines could be adequately deployed along coasts where spilled oil washes ashore based on the simulation results. We developed a spilled oil tracking autonomous buoy I (SOTAB-I), which tracks spilled oil autonomously and transmits useful data in real time. Sea trials using the SOTAB-I showed that it has efficient tracking procedures. The trials also showed that the drift of spilled oil is strongly affected by wind.In order to take into account the wind effect, a new SOTAB, which has a sail with a changeable size and direction, was developed, and sea trials were carried out. The experimental results revealed that the drifting velocity of the SOTAB-II was 3.1%-3.8% of the wind velocity along the wind direction. When the sail was completely furled, the drifting direction of the new SOTAB-II was different from that of the imaginary drifting oil. However, the drifting direction was decreased when the sail was completely unfurled. These results show the efficiency of the sail attached to the SOTAB-II.