a The domain of the ocean field experiments is located south of Martha's Vineyard, where the ocean surface sub-mesoscale velocity, remotely sensed from high-frequency-radar (HFR) measurements as described in ref. 11, is available within the hatched black polygon. The black rectangle represents the area of interest of the 2014 field experiment. b Tioga WHOI vessel, CODE surface drifter, whose GPS-tracked position will be marked with a white dot, and OSCAR Water Rescue Training manikins whose GPS-tracked position will be marked with a magenta triangle. c Photo illustrating a drifter and a manikin in water during the 2018 experiment. A drone-based video of the 2018 field experiment is available here17.