Design of small GPS drifters for current measurements in the coastal zone

Field observations of flows in coastal zone are scarce, but important for understanding the spatial variability of currents. The design of small, low-cost GPS drifters for collecting accurate Lagrangian data in the coastal zone is described. The drifters are intended for using in nearshore environments, lakes and estuaries over timescales of a few minutes up to several hours and are a low-cost alternative for applications which do not require drifter’s sea-going capability. Two field tests of GPS drifters in the south coast of Caspian Sea in Anzali port, Iran, in November 2008 and July 2009 were successful.