Traverse board

An old and approximate means of making out the course made good by a ship during a watch. It is a circular piece of wood marked with the points of the compass, with eight holes bored in each. Eight small pegs were attached to the center of the board, and each half hour one of the pegs was put in a hole on the compass point on which the ship had run during that half hour. At the end of the watch the mean course could be calculated from the positions of the pegs.