Linex Deluxe 9 Inch Protractor Triangle SEMAR - Regional British Admiralty Nautical Chart 1831:

British Admiralty Nautical Chart 1831: Arquipelago da Madeira is a standard nautical chart

4) Dredging or making way with an obstruction on one side – Two green lights or two diamonds in a vertical line to indicate the side safe to pass

UPC Code: 721002911087

There has been a controversial Oil Pollution Act passed by the United States

Multiple Methods of Use & Full Body Support – Allowing for safe and comfortable recovery

Linex Deluxe 9 Inch Protractor Triangle SEMAR - Regional British Admiralty Nautical Chart 1831:Most protractor triangles are 8 inches on the side. These have an extra inch. Since the triangle is larger, the printing is also larger and is in red and black, thus making the numbers easier to discern.