12v DC LIGHTING
Traditionally narrow boat lighting has been pretty limited. Taking its cue from mainly the more popular caravan market, you were lucky to be offered 2 or 3 basic styles. Fluorescent tubes and car type bulbs were about the extent of the choice. Luckily that has all changed with LED options now popular on narrowboats.



12v DC Lighting… LED’s
LED bulb lighting will by far and away be the most power efficient as far as connecting to your narrowboat battery bank is concerned. LED lights are also a safer solution, many other traditional bulbs generate a substantial amount of heat which doesn’t instill confidence when you’ve left your wooden clad narrow boat with a light on!
What are LED Lights?
A light-emitting diode (LED) is a semiconductor device that emits visible light when an electric current passes through it.
Buying a New Narrow Boat?
Double check with your narrowboat builder LED Lights are inclusive in the standard specification upgrade if necessary.
Replacement LED Bulbs Are Available
Our advice is to replace standard bulbs with direct LED replacements! Many LED bulbs are a straight plug in replacement for the older style.
How Efficient are LED Lights in Comparison?
Typically when replacing halogen bulbs LED Light bulbs you’ll save around 90%. Put another way it you can power 10 LED bulbs for the same amount of power as 1 halogen bulb draws!
LED lights Don’t Like Voltage Spikes!
LED’s do not like voltage spikes. They work best and give longer life if run on a smooth constant voltage. We recommend you buy the types that have protective diodes built into the circuitry. They are a little more expensive but will win in the long run.
12v DC Lighting… Bulb Options

MR11 / MR16 Bulbs
These Multifaceted Reflector Bulbs (aka MR) are commonly used in narrow boats for directional lighting applications such as undercounter lights, recessed ceiling lights & desk lights. The numerals (MR11 & MR16) relate to the diameter; measured in eigths MR16 is 16/8 and MR11 is 11/8. Most run on low voltage so can be directly installed within narrowboats. For 240v applications an inline 240v – 12v/24v transformer is required. LED Replacement bulbs commonly available.

Bayonet Bulbs – BA15s, BA15d & BAY15d
These were commonly used in narrow boat ceiling lights. Bayonet bases or caps (aka BA, often with a number after) The number refers to the base diameter (e.g., BA15 has a 15mm diameter). The lower-case letter s or d specifies whether the bulb has single or double contacts. BA15s bulbs have single contacts with parallel locating pins. BA15d bulbs have double contacts with parallel locating pins. BAY15d bulbs have double contacts with asymmetrical locating pins. LED Replacement bulbs commonly available.

G4 Capsule Bulbs
Commonly used in narrow boats for applications such as undercounter lights and recessed or surface mounted ceiling lights. These use a bi-pin connector. LED Replacement bulbs commonly available.

Festoon Bulbs
These are less common but still found within canal boats. Festoon bulbs are manufactured in two different versions or end caps. The end caps are either round or cone shaped, the more common versions found in canal boats are the cone style festoon bulbs. LED Replacement bulbs commonly available.

Fluorescent Tubes
These were commonly used in narrow boats and are know for there flickering and buzzing. The 12v Fluorescent tubes are commonly fitted with built inverters to increase the voltage for start up. If you are looking for replacement led tubes due to the built in inverters we recommend you replace both the tube and the fitting to avoid potential problems. LED Replacement tubes/fittings commonly available.
12v DC Lighting… Setting The Mood!
A narrow boats natural profile creates some fantastic opportunities for installing 12v mood lighting. The most common places considered for mood lighting are under the gunwales, low level mounted inside the boxed pipe work runs and on the front or sides of the bow and stern steps.
Some of the narrowboats we have been involved with designing are installing external mood lighting by fixing led rope lights to the underside of the stern rails/seating and in the bow mounted to the underside of the gunwales.
New to the market are ‘touch operated’ dimmable LED lights which are a great alternative to installing dimmer switches (see next section). The lights are switched on and off by actually touching the centre of the LED. Unlike traditional down-lighters which would be hot to touch, LED’s are actually cool
If you’ve got the opportunity to consider mood lighting whether on a new build or if you’re updating an existing boat you can achieve some fantastic results for a relatively small investment.
Dimmer Switches
Dimming 12v LED lighting is possible but not as easy as you might imagine. Within narrowboat standard 240v light switches are commonly used as switching devices. 240v light switches are perfect for the job and make 2 way switching easily achievable. You might be considering swapping your 240v switches for 240v dimmer switches, unfortunately it not that simple! 240v dimmer switches are just that 240v dimmers so they are design to regulate 240v not 12v which is where the problem arises.
12v Dimmer switches are available, you can even source ones that fit direct to a standard 240v back box. The problem comes that 240v light switches only utilise positive connections and many 12v dimmer switches require a positive and negative feed in and out which causes a problem if your considering retro fitting as you will be missing the negative feed.
If your fitting out a narrowboat from scratch, refitting or having one built for you this positive and negative requirement can all be catered for. If you are going down the 12v dimmer route consider whether you can use these for 2 way switching at either ends of rooms as our research has shown many only cater for only one way switching.
Top and bottom of it… Do your research on 12v dimmer switches!
12v DC Lighting
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