This Wheems & Plath Marine Navigation Parallel Ruler is a must-have for any boater or mariner. With its precision and durability, it is a reliable tool for measuring distances and angles on the water. The brand is well-known for its high-quality products, and this ruler is no exception. It is perfect for use with electronics and navigation equipment, as well as for drafting charts and maps. Whether you are a professional or a recreational boater, this ruler is an essential tool for accurate and safe navigation.