Coast Guard alert on proper navigation lights for sailboats

WASHINGTON, D.C. (LOG NEWS SERVICE)—The Coast Guard has issued a safety alert warning boat owners that the installation of improper navigation lights on sailing vessels may result in situations where the sailing vessel’s lights are not visible.

According to the Coast Guard navigation lights intended for use on power driven vessels may be different from navigation lights intended for use on sailing vessels. Although the horizontal arc of visibility is the same for all lights, the vertical divergence (i.e. vertical arc of visibility) requirements for lights on vessels under sail are larger to accommodate greater heeling.

Navigation lights that claim compliance with the navigation rules may meet the vertical visibility requirements for a power driven vessel; however, they may not comply with the vertical visibility standards for sailing vessels.  Manufacturer labeling may not indicate that the lights are designed for use on power-driven vessels only.

Annex I (COLREGs section 10 and Inland 33 C.F.R. part 84.16 “Vertical sectors”) prescribes the degrees and intensities that navigation lights must meet on the vertical plane.  Many boat owners may not be aware of the +/- 25-degree vertical light divergence requirement for sailing vessels, a 17.5-degree increase from the power-driven vessel standard.

The Coast Guard strongly recommends that boaters avoid purchase and installation of any light that does not present the required certification data and that retailers advise their customers to purchase certified navigation lights.

Installing a navigation light, designed for use on a power driven vessel, on a sailing vessel may result in the light losing visibility when the vessel heels beyond the narrower +/- 7.5-degree vertical divergence angle established for power-driven vessels. A sailing vessel operator in this situation would likely not realize that the sailing vessel’s lights were not visible when heeling beyond 7.5 degrees.