Yellowfin

Robotic surface vehicle from Woods Hole Oceanographic Institution, built by Peter Traykovski and adapted for Anne Cohen's reef work, that photographs shallow coral reefs along GPS-tagged tracks so the same colonies can be rechecked after heat waves.

Peter Traykovski, a coastal oceanographer and engineer, built Yellowfin to map seabeds and coastline change with sonar.² The vehicle is uncrewed and designed to move over shallow reefs without disturbing the coral.^1,2 The coral scientist Anne Cohen had him mount a GoPro under the hull so it photographs the reef continuously as it runs.² Depth, temperature and GPS position are recorded alongside the images.¹

Cohen's lab uses Yellowfin to find and follow "super reefs", reefs that come through marine heat waves.² The vehicle is driven along GPS waypoints in a lawnmower pattern of back-and-forth lines, taking two pictures a second.² In a day that comes to up to about 20,000 images over 40 miles of reef, each tagged with coordinates.²

Because the track is georeferenced, the team can return to the same section or the same colony on a later trip.² They can then see which corals bleached, died, recovered or were untouched.² After a survey Traykovski can send the vehicle back to a particular coral Cohen wants to look at.² The images also feed 3D reef models, which show how a colony's depth, angle and orientation relative to its neighbours may affect its heat exposure.² Cohen used to go through the images by hand.² The lab has started training AI models for the task.^1,2

The first deployments were on the reefs of Majuro, in the Marshall Islands, in 2024 and 2025.¹ A June 2026 account describes further testing there on an April trip.²