Weems and Plath 501V Vectormaster Navigation Slide Rule

An advanced navigation tool the circular slide rule provides for the solution of time speed and distance fuel consumption conversions multiplication and division. On the reverse the face of the Vectormaster permits rapid solution of problems involving vectors such as those encountered in current sailing the determination of true wind direction and force and the apparent wind to be expected on other headings. Given the position of a storm and the direction and speed of its advance you may quickly determine the course which will put maximum distance between your vessel and the oncoming storm. Instruction booklet included. Dims: 7'' square.