USCG issues safety alert regarding potential radio frequency interference from LED lights

It sometimes seems that as new products for fishermen/boat owners come to market, we discover unexpected limitations, side-effects, or the need for work-arounds.

This appears to be the case with some LED lights, a product that has become increasingly ubiquitous on many fishing boats.  Some LEDs, it seems, have been found to emit radio frequency energy that can interfere with the radio frequencies of TV, WiFi, FM radio, and – unfortunately — can mess-up VHF reception.  This latter concern is a potential hazard for commercial fishermen which is what prompted the Coast Guard to issue Safety Alert 13-18 last fall.

When you stop to think about it, there are many lights on most fishing vessels.  In addition to red, white, and green navigation lights, there are often spreadable work lights to light the deck and the field.  Inside, dome lights, under-cabinet lights, and engine room lights are often found.  I can presume, based on new boat coverage in these pages, that many of those who are fortunate enough to be commissioning a new vessel are probably also installing LED lights.

Additionally, other fishermen might be planning a winter project to replace their current incandescent lights with LED lights.  In either case, here are some things to consider.  The quality of the LED light bulb may matter a lot, as there are some on the market that cause interference with VHF and AIS (Automatic Identification System) communication.

There are several YouTube videos that illustrate the interference problem and suggest some work-arounds.  A video at shows an enterprising man capturing the radio frequency “noise” on his oscilloscope as he is trying to rectify interference from some new LED lights he installed in a workshop.  He placed a simple filter from a parts store in the electric service line and demonstrated that it reduced the interference.  In another video at a man who had replaced his car headlights with LED bulbs tries to remedy the interference they caused with his car radio.

His “fix” was to install a number of ferrite chaulks (aka chokes) on the power line to the lights. After installing several chaulks his FM channels were satisfactorily clean.

Clearly, the better approach is to purchase LED bulbs that do not emit radio frequency energy, rather than struggle with cumbersome work-arounds.  The website <www.doctorLED.com>  is an excellent source of information and tips.

One helpful component is the section titled “How to spot low-quality marine LED bulbs.” Although not foolproof, there are good hints. Caveat emptor —  buyer beware — the bulb packaging may not disclose whether the bulb generates radio frequency energy.

The Dr. LED brand provides a large variety of bulbs for the marine market.  The website claims that that they are tested according to the protocol described in the USCG Safety Alert 13-18 and meet FCC (Federal Communications Commission) Part 15B requirements.  If you are looking to replace your incandescent bulbs throughout your vessel, use the conversion tables on this website to be sure you have the correct voltage, bulb style, and bulb base.

Most fishermen are pretty good at deciphering the sometimes scratchy messages that come over the VHF radio — but clearly nobody wants radio frequency interference from LED lights to obliterate a serious Channel 16 communication.

Ann Backus, MS, is the director of outreach for the Harvard School of Public Health’s Department of Environmental Health in Boston, MA.  She may be reached by phone at (617) 432-3327 or by e-mail at <abackus@hsph.harvard.edu“>



•  Read the USCG Safety Alert 13-18 available at <https://www.dco.uscg.mil/Portals/9/DCO%20Documents/5p/CG-5PC/INV/Alerts/1318.pdf?ver=2018-08-16-091109-630>.

•  If you already have LED lighting on board, test your VHF and AIS systems to be sure your communication signals are clear, both incoming and outgoing.

•  If you plan to use LED lighting for home or boat, purchase reputable LED bulbs and test them for radio frequency interference prior to installation.