There are just a few basic tools needed for navigation, yet there are many, many options available—not to mention the unlimited number of gizmos and gadgets that do this or that job in special circumstances. The basics are a pair of dividers, parallel rulers, a simple ruler, and a protractor. Beyond that we venture into the realm of luxury, which is never far from the realm of clutter. Below are a few notes on the basic tools. You can click the small pictures for more details on the individual tools.
A bow is a tool that will hold its point separation once set, and it is set by a rotating knob in the center of the tool—as opposed to conventional dividers which are just pulled open or squeezed closed. A "speed" bow is one that you can pull open or close by hand without having to use the center knob. In other words, you can override the fine control of the center knob by firmly pulling or pushing on the legs themselves. This particular model has become the dividers of choice for the vast majority of professional navigators worldwide because of its ease of use and accuracy. This was also helped by the fact that it was imported by Weems and Plath which have a worldwide distribution network in nav tools and it sells for a very good price. Before this model appeared some fifteen years ago, quality speed bows were in the 30-dollar range and were awkward to use. This one is light weight, and easy to use. This one includes a pack of leads, so you can change its operation from dividers to drawing compass to draw arcs used in distance off measurements.
It takes a bit of practice to manipulate these without slipping, but after some practice it is quite easy. There are numerous styles and sizes of these. We recommend clear plastic, 15 inches long. An alternative to parallel rulers is a rolling tool called a parallel plotter, or more specifically, the Weems parallel plotter, named after its inventor. These are designed to roll without sliding, which they generally do fairly well, with little practice. Unfortunately, rolling plotters do not work well near the edges of charts, or over folds in the chart. We carry both tools underway and use the Weems plotter whenever possible, but immediately switch to parallel rulers if need be.
The 4" x 15" ruler we offer can be used with either the parallel plotter or the parallel rules to extend a line, or it can be used as a stand alone device to do the job of both parallel plotter and protractor. Some mariners prefer this one-tool solution to plotting, others are willing to carry an extra tool to expedite individual tasks. With the the "Navigator's Tool Pack" you can practice with each of these tools to see which meets your needs best. Parallel rulers and plotter are, of course, rulers in their own right, but we have enough need for longer lines and other special applications to justify having a separate ruler in the nav station. Same with the protractor.
For those starting from scratch on tool selection, we offer the "Navigator's tool pack" as a way to order all with one item, with an additional 15% savings.
Remember the above is a full set for all types of navigation and various other related plotting likely to take place in the nav station. The bare minimum tools required for navigation underway and for doing our home study courses would be simply the parallel rulers or roller plotter and the dividers. |