The Lagrangian perspective...
Lagrangian observations are recorded using BigEye beacons that transmit GPS position over a VHF radio link. In addition, the drifters each contained a handheld Garmin GPS 72 unit that internally recorded position every 3 minutes. For each deployment 11 or 12 drifters were drogued using a 5 m long holey sock centred at a depth of either 5 or 15 m. The experiments lasted between 5 to 18 hours. The measured GPS resolution was approximately 8 m. .
Stevens, CL 2010.
and Eulerian estimates of circulation in the lee of
Stevens, C. 2010. Short‑term Dispersion and Turbulence in a Complex‑shaped Estuarine Embayment, Cont. Shelf Res. 30 (2010) 393–402, http://dx.doi.org/10.1016/j.csr.2009.12.011