16th-century method of keeping track of the boards and traverses the helmsman had made during his watch in his attempt to make good the course ordered by the captain. The various boards must be resolved into north–south and east–west components which add up to the course made good. The distance sailed on each tack was recorded on the traverse board which normally hung before the helmsman. It was a circular piece of wood on which the rhumb lines were marked by equidistant holes representing hourly and two-hourly periods during which the ship sailed a particular course. Pegs attached to the centre of the board were put into the holes to mark the number of hours. At the end of the watch the mean course made good would be calculated from the position of the pegs. The officer of the watch would have decided the measured or estimated speed, from which all directions and distances made good would be calculated.
As literacy increased among seamen the traverse board was replaced by the log board on which the courses and distances were written up.
Subjects: Maritime History.