We do a lot of night travel, as well as occasional anchoring. The original Perko (the double-sided, oval one) had significant salt-water corrosion issues, and the bulbs never lasted long, presumably due to vibration while in use. The unit had 2 bulbs, so initially I dealt with this by just stockpiling a bunch on the boat, and changing them as needed. One night, after discovering that I had crossed the better part of San Francisco Bay, including the main shipping channel, without either bulb working, I decided it was time to do something about it.
I had previously tried a couple of the LED replacement bulbs from Dr. LED, but the end caps had corroded off. Many of the alternatives that I found at West Marine and other chandleries just weren't as bright. Even the manufacturers only claimed 2nm, while the original Perko was 3nm. Although, arguably, the requirement for our size is only 2nm, it just didn’t seem to be a bright idea to downgrade, especially given the quantity of traffic in the bay. Even in the day those catamaran ferries can sneak up on you if you’re not careful, and at night I want to be seen.
At first I considered getting some really bright LEDs and building my own, but I discovered that the USCG approves fixtures with a specific bulb. Although USCG certification is not required, if there was ever an incident, the burden of proof would be on me, in order to prove that the lights were sufficient, instead of a legal assumption that they were.
While I was looking through some of the USCG material on the subject, I came across something that indicated what they use on some of their small craft and decided to give it a try. It is a sealed unit, so corrosion will be inhibited, and when I installed it at Two Harbors it was one of the brightest lights in the harbor, which is saying a lot as some of those boats are much larger.
The only drawback is price, but I decided it was worth it for safety, as we are out at night a lot, and sometimes anchor out. MSRP is $249 for the 3NM360W, plus $25 for an optional photodiode to turn the light off in the day, when anchoring. A pole adapter is available for $40. It is basically a small block of plastic that lets you mount it to the top of the pole used by your existing light. If you are handy, you could probably make your own, but I was short on time.
This is not the “Steaming and Anchor” light, no matter what some salesperson may tell you.
The tube adapter is not the mount sold on the same page as the light, but is found separately, as an accessory.
Although the MISEA website lists the photodiode for anchoring as an option for the 3NM360W, some retailers list it as a separate model, 3NM360WP.
Here are the links to the parts on the MISEA website:
LED 3NM Anchor 360 degree, White
Pole Mount Adapter for Signal Mate Navigation Lights
If the above links don't work you can also browse to them on the
www.miseagroup.com website:
Products/LED Navigation Lights/Under 20 Meters/All Around Lights/LED 3NM Anchor 360 degree White
Products/Accessories/Plates and Adaptors/Pole Mount Adapter for Signal Mate