LED technology has been advancing rapidly since it was first developed 50 years ago and latest types have the potential to save a significant amount of battery drain, using only 10-20 per cent of the power needed by traditional incandescent bulbs. They also offer a very significant saving compared to fluorescent alternatives.
The benefit of this to many smaller sailing boats is immediately obvious – even in the UK a boat with no charging facility other than a solar panel can now realistically run navigation and interior lights with no other input. Similarly, when sailing offshore on larger sailing yachts, there was a time that wondering whether the battery would run the lights through the night often preyed on the skipper’s mind. However, with LEDs that use only a tiny percentage of vessel’s battery capacity this is not an issue.
Even larger yachts equipped with generators, and in theory almost unlimited electrical power, can benefit from installing LEDs – such vessels tend to be fitted with a huge amount of interior lighting. Although conserving electrical power was not his primary motive, a friend who changed the dozen or so halogen downlighters in the galley of his Swan 62 for LED equivalents reduced the power draw by almost 200W. Repeating that throughout the boat it translated to a lot less time with the generator running and helped reduce cabin temperatures in the Mediterranean summer.
A further theoretical benefit is longer service life – some models claim 50,000 hours, although in practice some of the early marine navigation lights had a higher level of premature failure than would have been expected. However, these problems are likely to be ironed out as the application of the technology in this area matures.
Drawbacks of LED lighting
While a traditional incandescent bulb is very low tech – it’s basically a piece of wire that glows when enough current passes through, LED lights are complex components with integrated electronics. This means that not all will work effectively with the variable voltages seen on board boats: a nominally 12V electrical system can increase to up to 16V when the batteries are being charged by the engine or shorepower chargers, and may reduce to well under 12V if the batteries are well discharged.
One of the recent changes that’s made a big difference to the aesthetic viability of interior lighting using LEDs is the now widespread availability of ‘warm white’ lighting. Previously ‘white’ LEDs produced a harsh bluish light, rather than a comforting and relaxing warm glow that accentuates the pleasures of life on board. Some people got round this by combining old and new technologies – using a oil lamp in conjunction with LED lighting. Warm white lights also produce relatively true colours when used behind red or green lens for navigation lights, whereas a cool white LED can be used for the white stern, steaming and anchor lights.
Replacing incandescent bulbs with LEDs is the cheapest option, at a cost of around £7 per light and may be a good option for lights of a single colour. However, unlike a conventional bulb, which the fine line of the filament forms a single light source at the centre of the lamp, the LED replacement is a cluster of LEDs with a much larger overall diameter.
The problem with this is that the clearly defined boundaries between the lamp’s different coloured sectors are only be achieved with the discreet single light source. Anything else is a compromise with a degree of blurring of the boundaries between the colours that may not satisfy the requirements of the IRCPS.
That’s why companies such as OceanLED, Lupolight and Nasa Marine have developed fully integrated sealed unit LED navigation lights. These use arrays of different coloured bulbs to ensure the sectors are exactly as proscribed by the rules. The downside is that they are relatively expensive, ranging from around £50 to a few hundred.
However, before splashing out large sums, it’s considering which lights it’s worth changing – conventional navigation lights on a motor boat powered by an inboard diesel engine use only a small percentage of the power that the alternator returns to the batteries. And the lights aren’t used when the engine isn’t running. The situation with sailing boats, however, is somewhat different and the masthead tricolour light may be run all night when under sail on a long passage.
Note that when specifying navigation lights and bulbs it’s important to ensure you choose items that are type approved by the relevant authorities the territory in which you keep your vessel – this can vary, for instance, between Europe, the USA and other parts of the world.
Anchor and emergency lights
LEDs are perfect for an all-round white anchor light and it’s possible to get them with an integral light-dependent switch, so that the light automatically comes on at dusk and turns off at dawn. As well as further reducing power drain, it also means there’s no prospect of the boat being unlit at anchor if the crew return from shore later that expected.
LED technology can also be used to good effect with torches, search lights and interior emergency lights. The batteries of these items will last many times longer than with conventional bulbs, which means the devices can also be much smaller.
The technology in this area is still improving, with those changes often rapidly filtering into the consumer market. We can expect the technology to continue developing, particularly in terms of miniaturisation, but we’re unlikely to see commercially available products that offer the pin-point light source of incandescent filaments for some time yet.
As the reduced power consumption of LED lights also tends to improve the lifespan of a boat’s batteries there are very few leisure boats for which it would not be cost effective to replace all frequently used bulbs with suitable LED equivalents.