Moitessier

In The Long Way, porpoises visited Bernard Moitessier from time to time and played in his bow wave. There is a passage in which he was visited by a huge number of porpoises as he navigated Stewart Island on his way to the open Pacific. Instead of playing, the porpoises traveled in a row, turning at right angles periodically. Eventually, Moitessier discovered he was off course, headed toward a dangerous reef. He corrected his course in the direction the porpoises kept turning. The porpoises stayed with him for hours until he was safely past danger, then disappeared.