Weems & Plath Marine Navigation Parallel Plotter

Works as intended but quality not the best. Plastic can warp easily.

These devices are used in plotting navigation courses and in this particular instance, the constantly evolving waters in the Gulf of Mexico. A parallel ruler is rather old-school and funky in comparison to these doo-hickies. EZ to order coupled with lightning-fast processing and delivery. Happy Camper!

Works good. Made out of 1/8" sturdy plastic (probably won't take bending at all). Wheels seem to grip plotting and chart paper reasonably well.It is about 12.5 inches long so you need a bit of room to use it - especially to keep the wheels on a level, gripping surface. It will go in my chart kit and out to sea.

I prefer this to a parallel rule. It is much easier to use on the smaller format of chart books. It's size and the roller aspect to its operation make it easier to use and less subject to slipping.

I know its great when my instructor won't stop taking it from me to do plotting. I should have purchased two, one for the instructor and one for me. Great item, Great price. You might need to hide it. ha!

This device is intended to make accurate navigational measurements. This design can be faster to use than parallel rulers. I have utilized this exact model on my teacher's yacht, and it works great. However, I have purchased three, and returned three. The first was broken. The acrylic ruler was broke in two. The second had 0.5 degree of looseness. The third is also noticeably loose. Unacceptable for navigation. Do not buy.

I am a Airbus A380 pilot and are required by regulation to ensure that the navigation system is following the proper course across oceanic areas by plotting on a chart. One of the complexities that can occur is Air Traffic Control issue a re-route which necessitates the determination of initial True Tracks and distances between successive waypoints. Normally this is done with a table and can take several minutes, however with this plotter the job is very easy, even on the table provided on the Airbus. Construction of a very high standard.

Never thought using one of these would be a big deal, until I got stationed in Germany. I have always used this product as a Surface Warfare Officer in the US Navy, and when I got stationed in Germany, found out that the German Navy uses these 2 plastic triangles to do the same thing. Rolling Wheems are much better, and that's why I ordered this product. Nothing like owning yourself what you use every day on a destroyer underway!