Paralock Plotter - The primary purpose of the Paralock Plotter is to enable the transfer of GPS positions rapidly, easily and accurately to and from any paper chart. The Paralock Plotter features three unique design concepts: a locking knob that allows the user to quickly plot a GPS position on paper charts, two sets of finger holes that enable finger tips to act as friction pads on the underlying chart, and, although shorter than standard size rules, the Paralock Plotter opens to the same width as conventional rules and therefore covers the same chart area. Parallel Plotter - This plotter is mounted on a roller that allows you to plot courses and parallel lines with simple direct transfer without the space required of traditional parallel rules or triangles. The two rollers keep the Weems plotter parallel as you slide it across the chart. This plotter contains distance scales at 1:20,000, 1:40,000 and 1:80,000 to fit N.O.S. Coast and Harbor Charts, as well as an inch scale. This plotter also includes a semi-circular protractor for measuring courses and bearings against meridian on chart, and two quarter circle protractors for measuring courses and bearings against parallel of latitude. Instructions for the Weems plotter are included. Ultralight Divider - The navigation dividers are fully adjustable and easy to use and are constructed of coated corrosion resistant marine alloy. Their gear synchronized arms allow one-hand use and provide excellent point alignment while the center wheel/extension bar construction allows for fast action precision adjustments. It has stainless steel points, is made in Germany and comes with a lifetime warranty. VEC Vectormaster - This circular slide rule provides for the solution of time, speed and distance, fuel consumption, conversions, multiplication, and division. The face of the Vectormaster permits the rapid solution of problems involving vectors, such as thos