Over in the P-31 topic area, Jordan Snyder asked about any interesting P-31 mods, including LED bulb replacements.
Although I don't have a P-31, Pearson Yachts tended to use a lot of the same hardware across many of their models, so I thought I'd post this response under the General Interest topic area, since it could apply to multiple boat models.
At this point, virtually all of the lights on our P-323 have either had LED bulb replacements, or have been replaced with sealed LED fixtures. Overall current draw for lighting is about one-tenth of what it was. Here's a summary of what I learned and some URLs.
First, an Important Observation.When selecting LEDs for marine use, it is important to select ones with a built-in "constant current" regulator, because the wide range of voltages normally present on a boat's 12v DC system can drastically reduce the lifetime of unregulated LEDs. Constant-current LEDs can be easily identified by the wide voltage range in their specs, eg: 10 - 30V. Unregulated ones will typically callout something like 12-15V. Don't buy these, even if they're lots cheaper! Better to cry once rather than cry often!
Detailed technical info here:
http://store.marinebeam.com/technical-info-1/Cabin LightsPearson tended to use 10 Watt single-contact bayonet base halogen bulbs (sometimes called "elevator bulbs") for the cabin lights. They put out plenty of light, but got very hot. You risked burning your fingers on them when reaching for the on/off switch on a rocking boat! Our P-323 used SEVEN of these!
Several companies make direct replacement constant-current LEDs for these. The light output is close to the same as the 10W bulbs, but they only draw 1W! And no risk of burnt fingers!
They come in "flood" and "spot" styles. I used the flood style on the nav station and in the V-berth, and the spot style in the main cabin, and have been quite satisfied with them. The color is just slightly less "yellow" than the halogens, but still a "warm white". The flood even comes in red if you want red light at your nav station.
Flood:
http://store.marinebeam.com/bayonet-led-bulb-6-led-power-cluster-reader/Spot:
https://www.superbrightleds.com/moreinfo/bayonet-bulbs/led-product/394/Bow Navigation LightsNavigation lights are a tricky topic, as they must be Coast Guard approved to be legal. The problem is that Coast Guard approval encompases both the bulb
and the light fixture as a single unit. This would require LED manufacturers to have their replacement bulbs tested in every possible fixture, a prohibitively expensive procedure, if it were even possible! This leaves us in the precarious position of having superior bulbs available that aren't legal to use. You could go ahead and do so, but be forwarned that if you are involved in a boating accident, especially at night, the insurance adjuster
will check if your lighting is Coast Guard Approved. Failing this question could provide grounds for denying a claim!
The solution is for the manufacturer to build a sealed fixture with LEDs that can then be tested and Coast Guard approved. Several manufacturers now do this.
Many of the '70s and early '80s Pearsons used "teardrop" style recessed bow nav lights on the port and starboard sides instead of a single fixture mounted up high on the bow pulpit. I located Coast Guard approved sealed LED teardrop fixtures that are drop-in replacements for the ones Pearson (and many others) used. They are much brighter than the incandescent ones they replaced:
Shark Eye Teardrop Style Lights
http://www.boaterbits.ca/products/shark-eye-teardrop-style-led-navigation-lights Steaming LightAgain, all the above comments about Coast Guard approval apply. Although the low power draw of LEDs is not really an issue here (its only on when you've got the engine running), the 50,000 hour lifetime is! No more climbing the mast to replace a burnt out bulb! This is what I used:
3NM USCG-Certified 225° Masthead (Steaming) Light
https://store.marinebeam.com/led-masthead-steaming-light/Anchor LightHere, power
is a big deal, because your anchor light is left on all night. Again, LED, sealed, CG aproved, and 50,000 hr life:
USCG-Certified LED Anchor Light
https://store.marinebeam.com/led-all-around-anchor-light/Spreader LightsOur original installation had a pair of round fixtures here with a single 10 Watt bulb each. When they were working, which wasn't often, they were about as effective as dim moonlight. Between corrosion and dead bulbs, I was up the mast far too often.
Since spreader lights aren't typically left on for long periods, I reasoned that light output, longevity, and reliability wewe more important than power draw, so I replaced them with a pair of sealed LED fixtures that had an array of five 3 watt LEDs each, a total of 15 watts apiece! They light up the deck like aircraft landing lights!
The only problem was that they came with a tiny U-shaped mounting bracket that was intended to be through-bolted. So I had a local machinist fabricate a set of stainless, flat baseplates that were curved to match the underside of of the spreaders, and weld the U-brackets onto them.
15W LED Spreader Deck Light
https://store.marinebeam.com/15w-led-spreader-deck-light-for-boats/Hope this all helps someone!
