|This article does not cite any sources. (March 2008) (Learn how and when to remove this template message)|
A Breton plotter, also known as a Portland Course Plotter, is a navigational instrument used for nautical navigation with charts. It is a ruler with a rotating rose that enables to plot a course on charts, while aligning the North of the ruler with the North of the chart.
The Breton Plotter was invented by Captain Yvonnick Gueret, a Breton seaman who developed the plotter during his experiences teaching navigation. He was a commander in merchant vessels, served on small fishing boats, delivered private yachts and taught navigation. He later extended the use of the plotter to air navigation for small aircraft.
|This standards- or measurement-related article is a stub. You can help Wikipedia by expanding it.|