Chandlery June 2006 Issue

A Gift for the Navigator

The Light Rule’s black letters on white background in the answer key (right side of top and bottom) will be white on black in the next version.

OK, here’s a test. Tired of the Caribbean circuit, you’re off exploring the North Korean coast when you see a ship showing the usual lights for a large power vessel underway, except for three all-around green lights on the masthead, below the steaming light. What’s worse, those masthead lights are splitting the side running lights.

Stumped? Well, you wouldn’t be if you had your handy-dandy Light Rule from Weems & Plath. Sure you might need a flashlight to read the thing, but if you worked fast, you’d find out what the lights mean before disaster struck­—or you struck it.

Point is, the Light Rule is a nifty device to have on board, but it won’t take the place of common sense. Whether you’re brushing up for your captain’s test, or just killing time in Bermuda quizzing your crewmates, it’s worth the $25.

Operating like a slide rule, the 4x15-inch Light Rule, we are told, contains every light combination in the International COLREGS. (If a reader want to test this claim, feel free. We’d rather polish brass than thumb through the COLREGS for an hour). It does not cover lights peculiar to U.S. inland waters or the fabled Western Rivers.

Made of flexible plastic, the rule works like this: Slide the inner card left or right until the lights you’re trying to identify align on the ship and tow on the outer sleeve. The inner card is glossy so the “lights” pop out, but still not bright enough to use in a dimly lit nav station. (Weems & Plath considered using LEDs, but they wanted the device to be small and affordable.) Once you’ve aligned the lights, look through the magnified “vessel definition” window for your answer. PS thought the magnified text could be more legible, and Weems & Plath said that the next version—with white letters on a black background in the vessel identification window—will be. The plastic packaging sleeve it is sold in tends to self-destruct, but the light rule fits quite nicely in a ski sock, where it won’t get scratched. A fun and useful learning tool, the Light Rule earns a spot in the PS nav station–even though we’ve no plans to cruise North Korea and find ourselves off the bow of a minesweeper.

Contact - Weems & Plath, 410/263-6700,

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