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Weems & Plath LIGHTRule™

If you have ever been on the water at night and wondered if the marine navigation lights you see are from an approaching or fleeing vessel, or if the vessel is a fishing trawler or super tanker, then LIGHTRule™ is for you. This simple-to-use vessel identification tool is inexpensive security for night travel and should be an essential part of the equipment found on any boat. LIGHTRule™ is also an excellent aide for navigation classes and Coast Guard exams. Click on the Documents tab on the left to see a high resolution view of the LIGHTRule™.


  • Identifies all COLREGS
  • Displays 60 light configurations
  • Displays 15 day shapes
  • Actual view of vessel for port, starboard, bow & stern lights
  • Visual guide for horn signals
  • Magnifying lens for clear readability of definitions
  • Durable plastic construction
  • Lifetime warranty


  • Length: 15.8 in (40.13 cm)
  • Width: 5.1 in (12.95 cm)
  • Height: 0.4 in (1.02 cm)
  • Weight: 0.4 lb (1.02 cm)
  • UPC Code: 721002003430
  • HTS Code: 9017.20.4000
  • NSN: 6605-01-556-9420

Warranty Information

High Resolution Overview of LIGHTRule

Shipping is fast and FREE across the USA for all orders $199 or more. For more details about shipping see the full shipping page here.

We offer 30 Day Easy Returns. If you decide you don't need a product we'll take it back so long as it is in original and re-saleable condition. See the full details here.

Please see this page for our Texas Electronics Shipping & Return Policy:

Found a better price online? We'll match it or beat it if we can. 

All you need to do is let us know via phone or email ( and we'll let you know what we can do.

You will need to provide evidence of the better price online and it must include any shipping or taxes charged by that site. i.e. It needs to be the total price.

This only applies to new products, it does not apply to used condition products.