Satellite-tracked drifter that follows near-surface currents
By Pacific Coastal and Marine Science Center
2012 (approx.)

Detailed Description
Underwater view of satellite-tracked drifter following near-surface currents off Guam in 2012. Similar drifters were used to track coral larvae in the Hawaiian Islands during the July 2013 spawning of the reef-building coral Montipora capitata.
Sources/Usage
Public Domain.