LEDs Save the Night


Retrofitting our cruising boat with LEDs drastically reduced our energy bill and significantly improved the lighting experience below decks  (published November 2014)

Rosie and I and our boat partners Tony and Judy Knowles spend a lot of time cruising and living aboard on Lime’n, our 15 year old Jeanneau 45.2, so we are very aware of our battery capacity, our charging ability and the daily energy draw from all of the electrical fixtures and the electronics. While underway, the fridge, autopilot, electric winch and running lights are the major draws while at anchor the houselights, anchor light and the fridge consume the lion’s share of the energy stored in the batteries.

We have a 300 amp hour house battery bank and we charge this with an 85 amp engine alternator and an 85 watt solar panel, which produces just enough power to keep the fridge cold and run a few house lights. But, if the weather is cloudy, the energy balance starts to slip into the red and we have to run the engine. We do this despite knowing that running the engine at low revs is bad for it. This is a common problem for most cruisers, which is why you see so many live aboards with massive solar arrays and wind generators on their boats.

So, what is the simplest way to cut your energy bill while expanding your ability to burn lights till your heart’s content? The answer is to replace your lights with LEDs.

Tools of the trade
Tools of the trade

After doing some research, we contacted our friends at IMTRA for help. The company, based in New Bedford, Mass., has pioneered the field of LED technology and lights for the marine market. They manufacture most of the lights they sell in the U.S. and also distribute high quality lights from manufacturers in Germany and elsewhere. Without going into too much detail, suffice it to say that all LED bulbs and light fixtures are not equal. In fact, the technology has evolved rapidly in the last five years to the point that the 2014 generation of bulbs and fixtures are hugely superior in look, reliability and energy efficiency to those of only three or four years ago. We wanted a one-stop shop for the houselights and wanted to be on the cutting edge of design and technology, and that’s why we turned to IMTRA.
The big decision was whether we should use our existing fixtures and replace only the bulbs with LEDs or bite the bullet and upgrade all of the fixtures to dedicated, modern LED units. The cost difference was significant. But the look and light coming from new LED bulbs in fixtures that were not designed for them was also a consideration. In the end, the light from the dedicated LED units was much softer, had a bit more yellow, which gives them a pleasant and familiar glow, and were much more stylish than our old fixtures. So, it was out with the old and in with all new lights throughout the interior.

Since IMTRA does not make or distribute running and anchor lights, we first turned to our buddies at AB Marine in Middletown, RI to see what they had to offer. Our goal was to install a masthead tri-color light that had a 360-degree anchor light built into the fixture.

Our existing incandescent running lights were fitted with 20 watt bulbs that would give the required two-mile visibility. But with three 20 watt bulbs burning all night, we were churning through five amps per hour or 50 amp hours through an 10-hour night. At anchor, the existing  20 watt anchor light consumed 16.66 amp hours through a 10 hour night.
AB Marine carries a very well made brand of lights from Signal Mate and the tri-color-anchor light combo unit fit our needs perfectly. With the mast down during winter storage, we were able to replace the old anchor light fixture with the new Signal Mate unit. The old light needed only two wires running inside the mast while the new light required three. Luckily, when the boat was built, Jeanneau had been thoughtful enough to run three wires to the masthead.

The result of making the change to the LED masthead lights has been dramatic. While the incandescent anchor light used to burn 16.66 amp hours through the night, the new LED anchor light, rated at three watts, consumes only 2.5 amp hours. At sea, the masthead tricolor LEDs are just as efficient and consume a meager 2.5 amp hours through a 10 hour night passage compared to 50 amp hours with the old lights.


We had decided to replace all of the incandescent lighting fixtures on the boat with new LED fixtures. That part was easy. Deciding which lights to use from IMTRA’s large catalog of new lights was more of a challenge that required some trial and error. It was very helpful that IMTRA could send their able associate Mike Moriarity down to the boat with a box of samples and options so we could get a feel for what would look good on the boat and what would provide just the right light qualities.

At the outset, we had intended to use IMTRA’s new Sigma lights for all of the recessed overhead lights, of which there are 16 in all four cabins. These new lights have a built-in dimming capability and can be either recess mounted or flush mounted. The existing lights were mounted in holes in the headliners and moldings that were too small for the Sigma lights, and to use the dimming function we would need to run a third wire to each of the 16 positions behind the fixed liners. So, we opted for another model known as Hatteras lights.

New lights at the nav station
New lights at the nav station

Retrofitting the Hatteras lights was very easy. Anyone who regularly works on their own boat can replace one of these lights in 10 minutes. You simply pop the old light out of the liner, cut the two wires, strip and join the positive and negative leads to the new lights, pop these into the holes in the liners, screw them in place and twist on the stainless steel bezel.  Mike and I replaced all 16 overhead lights in under two hours. The 16 old lights each drew 10 watts or 160 total. The new lights draw 3.3 watts or 53 total.

The galley runs along the port side of the saloon and had been lit by strip lights that each drew 20 watts. We tried a couple of different styles of strip lights here and finally decided on a pair of very modern LED strips that swivel and have built in dimmers. These Resolux 853 strips give plenty of soft light for working in the galley and then can be swiveled away slightly and dimmed while we sit at the dinette table for dinner. We used the same Resolux model for the strip light over the chart table and this too can either be bright for working or dimmed for a more peaceful mood.

Because the Resolux lights do not have a red option for night vision, we decided to add a 17th Hatteras with a red bulb right over the chart table for night sailing. This is the only red light below. But, the Resolux strips have very faint white and red glows on the switches, which give off a trace of light that is just enough to get around the saloon once your night vision has kicked in. The old strip lights drew 20 watts each. The new LED strip lights draw 10 watts so we have made a 50 percent improvement in efficiency and have better looking and much more adaptable fixtures.

The galley with new strip lights
The galley with new strip lights

Like the Hatteras lights, retrofitting the Resolux strips was very simple and took about 10 minutes each.
Reading lights are essential on a boat you are living aboard. Even with LEDs, you don’t want the overhead lights glaring all the time and it is helpful for those of us with glasses to have bright reading lights strategically placed in the dinette and over the bunks. On Lime’n, there are two reading lights in the dinette and two on both sides of the forward double bunk. We had small swiveling, 10 watt lights in the dinette and next to the double berth. Above the berth there were two gooseneck lights with 10 watt bulbs.

We didn’t have a clear idea of what we wanted here. Mike had brought several samples and one called Munich intrigued us because it was built in bright stainless steel with a white glass shade, it swiveled and could be dimmed. But in the dinette, the installation put the glass shade very close to a cabinet door. Tony and I hemmed and hawed and finally decided to go with the Munich lights.

Munich light
Munich light

For the forward cabin, we decided on the Munich lights for the side reading lights and brass gooseneck lights over the bed that would look very nautical. IMTRA sent us the lights and we set out to install them. As soon as we had the gooseneck lights in place, we realized we would have to secure these with a bungee cord every time we put to sea. That seemed impractical, so we opted to replace them with Munichs of which we were now using six.
In the dinette, the old lights had been recessed into the headliner. The Munichs are surface mounted so we had to cut eighth-inch teak pads to cover the holes and on which to mount the lights. We had some old pieces of teak lying around the basement, so we cut two pads with a hole saw and were in business. All we had to do was wire the new lights, secure the bases to the pads and screw the pads into the overhead while hiding the old holes.

In the forward cabin, the wires for the goosenecks stood out from the bulkhead and would not fit inside the Munich’s base. So, we cut two more pads out of spare teak and then with a smaller hole saw and chisel basically routed out the backs of the pads to make room for the wires once the pads were screwed flush to the bulkhead.
We attached the Munichs to the pads, wired them up to the existing positive and negative wires, tucked the wires into the backs of the pads and screwed them to the bulkhead securely. They looked great and as though they had always been there.

Given the trial and error with lights, the need to cut four teak pads and the fiddling with everything to get the lights to fit, Tony and I probably spent a couple of hours finishing the project. The total time it took for two reasonably handy men to completely refit every interior light aboard Lime’n was under five hours.

Even in our spacious 45 footer that can and has fit 22 people below decks for a party on a rainy evening, quality, adjustable lighting makes a huge difference in how you react to the spaces. Our original goal was to retrofit LEDs to cut our energy bill by as much as we possibly could. But in the process we have significantly upgraded the whole ambience and interior experience of the boat.

The after cabins now have recessed lights that are bright and great for reading without the residual heat from incandescent bulbs. The chart table has a dimmable strip light and a red night light both of which work well when sailing at night.

The whole main cabin can be fully illuminated with the overhead lights or the spaces can be dimmed and defined as you swivel the strip lights and dim the reading lights.
The forward cabin has four overhead lights in two pairs, so you can either light the berth or light the open area for dressing. Over the berth, the two Munichs on the bulkhead swivel can move and dim to exactly the position and intensity you need for reading. And, when you want to read while your bunkmate sleeps, the sidelights can be aimed specifically where you want the light without shining it on the other person. To have gained this very refined aesthetic improvement to Lime’n seems like a huge bonus considering we had simply set out to achieved energy efficiency.
But the efficiency is still a big part of what retrofitting LED light fixtures is all about. On deck we have reduced our energy bill by more than 90 percent. Down below, we have cut the energy bill by 65 percent.

LED fixtures are more expensive than those for incandescent lights but to us the trade off is well worth it. We have to spend less energy on lighting, which means we have to generate fewer amp hours with solar panels and the alternator. And we can live without a wind generator.