We had done well to heed the advice of Mamadou, to wrap up against the chilly Mauritanian night and the bumps of his boat. "You ll be sore long before dawn," he had winked, "stay alert by counting my catch, on the fingers of one hand if it s like it was last week." In the distance, west-north-west, under the fleeting light of a moon, lights jerk and bob and swing like dancers grouped above the waves. The whish of the wind is broken by an occasional barked comment in the dark, or a fisherman chatting into a mobile phone. Mamadou s solemn face is almost golden from his lantern, except when he turns on his hand-held computer. Then it beams the image, a ghost-like grey, of a satellite-guided map as if he didn t know his exact position anyway...