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A slide-rule guide to US aids to navigation, rules of the road and the Intracoastal Waterway.

Limited lifetime warranty from Weems & Plath on the movement, for as long as you own the instrument. View the warranty terms (PDF)
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Shipped insured and fully tracked directly from the manufacturer's warehouse in Denmark or England. Free delivery in the Netherlands from € 75.
14-day right of withdrawal under European law, with manufacturer warranty handled by us. Contact us first and we send you a return note.
Cruising or chartering in the United States? ROADrule USATONS identifies the most common US aids to navigation, rules of the road and manoeuvring and warning signals.
Ready for American waters
38 navigation-aid definitions, 12 rules of the road, bridge lighting and Intracoastal Waterway aids, all legible through the built-in lens.
For European waters choose the IALA or CEVNI versions.
Key features
- US aids to navigation
- 38 definitions
- Bridge lighting and ICW
- Magnifier
Specifications
| Feature | Detail |
|---|---|
| Brand | Weems & Plath |
| Type | Navigation aid slide rule (US) |
| Dimensions | 407 × 133 mm (16 × 5¼ in) |
| Content | 38 definitions, 12 rules, bridge lighting, ICW |
| Material | Plastic with magnifier |
| Warranty | Weems & Plath Limited Lifetime Warranty |
| Weems & Plath item number | 290 |
| EAN | 0721002004192 |
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Explore our navigation aids and parallel rules and plotters, or see the full range on our Weems & Plath brand page.
Weems & Plath has served navigators from Annapolis, Maryland, since 1928. Shipsclocks.com supplies this item with friendly service in English.
Frequently asked questions
Is it useful in Europe?
No, it is specific to US waters.
- Material
- Plastic







