Parallel-Lineal
PARALOCK PLOTTER Weems & Plath

This GPS parallel rule, in a compact size, is particularly suited for use on modern small chart tables. 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.

The most inventive feature of this patented device is the locking knob located at one of the four pivot points of the parallel plotter's cross-arms. This knob enables the two rulers to be fixed in any given separation which allows rapid determination of GPS position.