Grid compass

It is a design of magnetic compass that facilitates steering a steady course without the risk of parallax error.

He has only to steer the craft so that the N/S compass needle lies parallel between the lines of the overlay disc.

[2] Although sophisticated electronics have taken over for commercial navigation, light aircraft, gliders and yachtsmen still use the grid compass because of its simplicity and ease of use.

The compass card is in the form of a bold parallel sided arrow which indicates magnetic north.

The craft comes on to the required course when the arrow on the compass card is parallel with the lines on the ring.