Drifting away from reality : A cheap way to get lagrangian measurements

Beauty may sometimes lie in the eyes of the beholder, but in science it always lies in simplicity. We tested a very simple concept to get drifting platforms  that we could track and equip with sensors. We equipped an available floating device with a commercial GPS tracking system.  We tested this in several campaigns ( Italia, New-Caledonia, Tunisia and Guadeloupe) to study surface drifts. Later, we added chemical sensors to collect of lagrangian measurements. Here we present  the general setting of the drifter and the results of the first tests, which proved its efficiency and robustness despite its cheapness and its simplicity to use. We also discuss possibility of adding various kinds of sensors.