Posted by: towmasters | October 14, 2009

Old-School Plotting & Navigation Tools For The Discriminating Mariner – Part I

This post begins a series that will periodically focus on older, or just plain old, practices, technologies and equipment that still have functionality and usefulness in the present-day work environment. The subject du jour is paper charts and, more specifically, the tools we use to plot (plot?) on them. Yes, believe it or not, you might actually want (or need) to do that every now and again should the electronic gizmos fail. You may well find yourself in the position of having to physically plot a course, fix your position, calculate safe distances, figure out eta’s, etc. Wouldn’t it be nice to have quality tools with which to work?

We’ll start with the “latest” in old technology; the pencil compass. Over the years I’ve occasionally seen them in the wheelhouses of various vessels. Usually they are cheap crap, like what we “old folks” used in grade school back in the day. But Weems & Plath has now brought out the heavy artillery, the German-made Professional Brass Pencil Compass.


As you can plainly see, this is old-school done right: 8 inches of heavy solid brass with a stainless steel point and a large knurled knob for clamping the pencil securely in place. There’s no screwing around with those tiny “leads”, and it’ll swing up to a 24-inch circle. The angle of the pencil is adjustable, as well as its length. What the hell do you do with one? You can use it to plot a fix using three or more radar ranges while in coastal navigation. For voyage planning you can use it to mark off safe-distance ranges from various navigational aids or known hazards on a nautical chart. It could also serve as a leather punch or would be handy for piercing little cubes of cheese and fruit while enjoying a snack on the mid-watch. If the need arose it could work beautifully as a stabbing weapon while you’re engaged in desperate, hand-to-hand combat with boarding parties of Somali pirates. The uses are practically endless! It lists for $57.99 from W&P, but you can get it for just $46.99 at Landfall Navigation in Stamford, Ct.

Next up are dividers. You can get either straight leg…..


or one-hand versions…..


… 7 or 8-inch lengths. They’re made of polished brass with stainless steel points. Landfall has the straight patterns for $27.99 and $33.99 and the one-hand types for $37.99 and $40.99. They are heavy-duty. They exude quality when held in hand. They are built to be well used and to last. There’s a lot to be said for those qualities in our stupendously wasteful, throw-away society.

Now it’s time for parallel rules, and forget about aluminum arms: you want brass whenever it’s available for the weight and steadiness it brings. Weems & Plath still makes them in a 15-inch length, which is generally the most useful size on a cramped chart table.


If you need a larger size then aluminum-legged it must be, but at the 24-inch length the overall weight is inherently greater so knocking them out of alignment as you walk them is somewhat less of a problem than with the smaller sizes.


Landfall has them both for $35.99 and $38.99 respectively.

Functional though the large, aluminum-legged version may be, brass still has way more class. Taking into account the different shapes of the arms, it’s also far more elegant for the discriminating navigator. Maybe that’s why Weems also offers the Elegant Navigation Set. It come’s with the 8-inch one-hand dividers, the 15-inch brass parallel rules and a small brass compass that you can use as a paperweight on the chart table, all fitted neatly into a varnished wooden box with brass hardware. That’s as old-school as it gets and you can get it for $109.99 at Landfall.


Finally, I’ll throw in ye olde Nautical Slide Rule for good measure.


It’s been around for as long as I can remember, in what appears to be an unchanged state, and is as simple, timeless and foolproof a navigation tool as humans have ever been able to devise. Well, maybe fool-resistant might be a better term to use. Anyway, it’s yours for $19.99 from Landfall and it’s worth every penny. Kennebec Captain made a fine post about it back in January with Nautical Slide Rule – More Than Meets the Eye. This is required reading for the thinking mariner…..and those that should be thinking but aren’t.


  1. 45, 45, 90 all the way.

  2. I’ve got the big, brass compass. Things ROCK and are quite handy for LARGE circles and such for corrections.

  3. I like the look of that compass. Clean and simple.

    The best compass I ever had I found in a stationary store in Japan in the drawing materials section. Heavy duty, no gears to strip and the leg with the lead extended when you needed a little extra reach. I hated the crappy compasses and dividers in the Navy supply system.

  4. Nice post. I do like the feel of the heavy dividers when I use them to navigate. I had not even considered their value for snacking or hand-to-hand combat. Thanks!

  5. […] Plath has now brought out the heavy artillery, the German-made Professional Brass Pencil Compass.Keep Reading on Towmasters: the Master of Towing Vessels Assoc. Forum >> October 24th, 2009 | Tags: Maps and Charts / Navigation, Tradition | Category: […]

  6. […] out the previous posts (Part I, Part II, Part III & Part IV) in this […]

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