Ocean drifters measure currents and other parameters, such as temperature and salinity, to further deepen our understanding of the oceanic environment. The main difference between the two major types of ocean drifters are their placement in the water column. As their name suggests, surface drifters remain in the top one meter (three feet) of the water column whereas deepwater drifters are suspended to a certain depth below the water surface to track subsurface currents.
Deepwater drifters are often made in the shape of a cylinder with cutout holes sometimes made out of biodegradable bags that help to provide stability. This cylinder is then attached to a surface buoy by a cord or chain and weighted to be suspended to certain water depth.
Clips used in public presentations should be credited “Courtesy of Ocean Exploration Trust/ Nautilus Live.”