Traverse board

A Pinnkompass, also plug or cutlery compass, wax or Dutch board called, was a tool for dead reckoning in the earlier sailing ships.

It consisted of a board with the cardinal points, similar to the rose displays, and holes in eight concentric circles. The eight circles represent the eight bells, four hours of guard at the helm. Every half hour (= 1 glass) put the helmsman a small stake ( " embroidery " ) into the hole on the Pinnkompass, which corresponds to the course, which was held at this time.

As a supplement in a field below the wind rose, the speed - measured with a log - held, which was driven during the corresponding glass. Thus in the end the guard of the total driven course reconstruct and transferred to a chart.