Figure 1.

(a) The tracks of 22 hawksbill turtles from their nesting beaches on Diego Garcia island, to their foraging sites on the Great Chagos Bank, Pitt Bank and Centurion Bank. Stars denote the foraging site. Colours are simply to aid clarity and reflect the target, i.e. the foraging site of each turtle, with red and yellow indicating north and south of the Great Chagos Bank, dark blue Pitt Bank and grey Centurion Bank. Banks with water depths shallower than 200 m are shaded in darker blue. Arrows indicate the direction of travel for the most circuitous route. (b,c) Current vectors are shown for two examples of turtles migrating to the Great Chagos Bank. The current vectors are shown every 6 h throughout each track and so the vectors appear closer to each other when the turtle is travelling slower.