What can an SLDMB tell us about the waters it is deployed in?

• A. Wave height
• B. Salinity
• C. Temperature
• D. Total Water Current

Answer: (D)

A drifting buoy’s primary purpose is to reveal how the surface water is moving. A Self-Locating Datum Marker Buoy floats on the ocean surface and uses GPS to report its position over time. By plotting its path, you can see how fast and in what direction the water itself is moving at the surface. This makes it a direct tool for understanding the total water current in the area, which is exactly what drift modeling in search and rescue relies on.

Wave height isn’t the main data stream from this buoy, and while some units can carry additional sensors, salinity isn’t the typical measurement focus, and temperature may be collected only as a secondary data point. The essential value for SAR drift analysis is the current vector derived from the buoy’s drift, not the other properties.