LINEX PARALLEL RULER WITH CAPTAIN FIELD’S GRADUATIONS – ALUMINIUM ARMS
$43.41
$71.19
Description These emulate top-of-the-line professional parallel rulers, as would be found in the hands of many professional ships officers today. The Captain Fields scale can best be described as starting life as a 360° protractor, subsequently folded in half along the N/S axis and elongated to fit the length of the ruler. The scale is used against a meridian of longitude to read direction in degrees true; this eliminates the need to walk all the way to the compass rose. The scale print on the ruler is much larger, and can be read with greater precision than the compass rose as printed on the chart. Few non-professionals are taught to use a Captain Fields scale, yet it is a very big improvement on the charted rose.
