7 Things to Consider When Upgrading Yacht Lighting: A Refit Guide

• Confirm your electrical system voltage (12V or 24V) before ordering a single fitting
• Match the IP rating to the position, not the product description — the same light belongs in different categories depending on where it is installed
• Measure existing cutout dimensions before selecting replacements: a 1mm difference can mean a full refit of the headliner
• Choose colour temperature and CRI before you buy — both are impossible to judge from a product photo
• Plan the cable run and cross-section before installation, not after — undersized cable is the most common cause of reading light flicker
• A consistent design series across all positions produces a more coherent result than mixing products from different ranges
• Dimming is almost always worth adding during a refit, even if the existing wiring does not support it

About This Guide

Upgrading the lighting on a yacht during a refit is one of the highest-impact improvements available for the money. It affects how the interior looks, how comfortable it is to live aboard, and how safely the boat can be handled at night. It is also one of the areas where small specification errors — wrong voltage, wrong IP rating, wrong dimensions — create disproportionate problems.

This guide covers the seven decisions that matter most when planning a lighting upgrade, in the order they should be made. Working through them in sequence avoids the most common refit mistakes and ensures the finished installation performs as intended.

How This Guide Was Written

The considerations in this guide are drawn from Cabin Denmark’s experience supplying marine lighting to yacht builders, refit yards, and private owners across Northern Europe since 1977. They reflect the most frequent specification questions we receive and the errors we most often see in refit projects that arrive for correction.

The 7 Things to Consider

1. Check Your Voltage System First

Confirm whether your yacht runs on 12V, 24V, or both before specifying or ordering any fittings. Installing a 12V-only light on a 24V system will result in immediate failure; installing a 24V light on a 12V system means it will never reach full brightness. This sounds obvious, but it is the most common specification error in lighting refits.

Most yachts under 40 feet run on 12V DC. Many larger yachts, particularly those built in the last 20 years, run on 24V. Some vessels have mixed systems — 12V for navigation electronics and 24V for propulsion-related systems. Before specifying any light, check the circuit voltage at the installation point, not just the battery bank nominal voltage.

The safest specification is a fitting rated for 10–30V DC. This covers both 12V and 24V systems with headroom for charging voltage (which can reach 14.4V on a 12V system and 28.8V on a 24V system). It also future-proofs the installation if the electrical system is ever changed or upgraded. All reading lights and the majority of courtesy lights in the Cabin Denmark range carry this wide voltage specification.

Pros of wide-range (10–30V DC) fittings

• Compatible with both 12V and 24V systems
• No converter or additional wiring required
• Handles charging voltage peaks without risk
• Future-proof if the electrical system changes

Cons of wide-range fittings

• Slightly higher component cost than single-voltage fittings
• Requires checking that the circuit protection (fuse/breaker) is rated appropriately for the actual system voltage
  

2. Match IP Ratings to Location, Not to the Product

The IP rating a fitting requires depends entirely on where it is installed, not on what it is called. A product labelled “interior reading light” still needs IP67 if it is installed in a wet area. A product labelled “deck light” can be installed at IP65 if it is in a sheltered cockpit position. The label is a product description; the IP rating is a technical specification.

In practice, yacht cabins are rarely fully dry. Hatches, ports, and companionways admit condensation and spray. Courtesy lights at floor level encounter standing water. Lights in heads and wet areas may be directly splashed. The IP rating must reflect actual conditions, not the best-case scenario.

IP Rating Guide for Refit Positions:

 

A practical rule: If there is any chance the fitting could get wet in normal use, specify IP67. The cost difference between IP65 and IP67 is small; the cost of replacing a failed fitting in an awkward position is not.

3. Measure Existing Cutout Dimensions Before Ordering

Before specifying any replacement fitting, measure the existing cutout diameter or dimensions precisely. This applies to recessed downlights, courtesy lights, and any fitting that installs into a pre-cut hole. A 1mm difference in cutout diameter can make a direct replacement impossible without cutting new holes or fitting cover plates — both of which add time, cost, and visual compromise to the refit.

Older halogen downlights often used non-standard cutout sizes. Some courtesy lights have proprietary housing dimensions. Measure the existing hole (not the fitting itself), check the new fitting’s required cutout dimension in its datasheet, and confirm they match before ordering.

What to measure:

• Recessed downlights: Cutout diameter (not housing diameter)
• Courtesy lights: Width and height of the housing recess, or cutout diameter if circular
• Reading lights: Mounting hole centres and cable entry position
• Deck fittings: Cutout diameter and headliner or deck thickness

What to check in the datasheet:

• Required cutout diameter or dimensions
• Mounting depth (fitting must clear any structure behind the surface)
• Cable entry position and required clearance

If a direct replacement is not available, a cover plate solution — a slightly larger-diameter trim ring that covers the old cutout — is a clean way to bridge the size difference without recutting.

4. Decide on Colour Temperature Before You Buy

Colour temperature cannot be judged from a product photo and is very difficult to change after installation. Choose it before you order, test it if possible, and apply it consistently across the entire interior.

Colour temperature is measured in Kelvin (K). Lower values are warmer; higher values are cooler and more clinical.

 

For most yacht interiors, 2700K is the correct specification. It matches the warmth of traditional incandescent and halogen lighting, which most owners are replacing. It complements teak, leather, linen, and painted surfaces. Cooler temperatures make quality materials look flat and institutional.

The common refit mistake: Installing 4000K LEDs because they were cheaper or more readily available, then finding the saloon feels like a ship’s mess hall rather than a well-designed interior. Changing colour temperature after installation means replacing all fittings.

Mixing colour temperatures within the same interior — 2700K in the saloon and 4000K in the galley, for example — creates a visible discontinuity when moving between spaces. Choose one colour temperature and apply it throughout the accommodation.

5. Add Dimming Before the Wiring Is Closed Up

Dimming is significantly harder to add after a refit than during one. The wiring requirements for a dimmable circuit are the same as for a fixed-output circuit — the only difference is the fitting itself and, in some cases, a separate dimmer module. Adding dimming capability during a refit costs almost nothing extra; retrofitting it after the headliner is back in place is a full job.

For yacht interiors, dimming transforms the quality of life on board. The ability to move between full task lighting and low ambient light without changing fittings makes a significant difference for evening use, night watches, and sleeping arrangements in shared cabins.

PWM (Pulse-Width Modulation) dimming is the correct technology for marine LED fittings. It delivers flicker-free output at any brightness level and maintains colour quality at low settings. A touch dimmer with memory function — which returns to the last-used setting at switch-on — is the most practical choice for berths and saloons used regularly.

Pros of specifying dimmable fittings during a refit

• No additional wiring cost vs. fixed-output fittings
• Transforms the flexibility of the interior lighting
• Memory function eliminates repeated adjustments
• Same installation time as non-dimmable alternatives

Cons

• Dimmable fittings cost slightly more than non-dimmable equivalents
• PWM dimmers require a minimum load — confirm fitting compatibility with any external dimmer used

6. Prioritise CRI for Living Spaces

CRI (Colour Rendering Index) is the specification that most directly affects how the finished interior looks, and it is the one most often ignored in budget refit decisions. A light with CRI 70 will make a beautifully crafted teak saloon look flat and dull. A light with CRI 90+ renders it close to how it looks in natural daylight.

CRI is independent of brightness and colour temperature. A warm-white 2700K light can have CRI 75 or CRI 95 — both will look similar in a product photo but very different on board. The difference is most visible on wood finishes, upholstery, and any surface with a range of tones. It is less relevant in utility spaces like engine rooms where colour accuracy has no practical value.

For all accommodation spaces — saloons, berths, heads, galleys — CRI 90 or above is the recommended minimum. The price premium over CRI 75–80 fittings is modest; the visual difference is not.

How to identify CRI in product specs:

• Listed as CRI, Ra, or Rа followed by a number (e.g. CRI 92, Ra >90)
• If not listed at all, the value is almost certainly below 80
• Extended R9 value (saturated reds) above 50 is a useful additional indicator for spaces with warm wood tones

7. Plan the Cable Run Before Ordering

The cable run — path, length, and cross-section — should be confirmed before fittings are ordered, not after. The required cable cross-section depends on the current draw of the fitting and the length of the run. Undersizing the cable is the most common cause of reading light flicker and premature LED failure in refit projects.

For most yacht reading lights and courtesy lights, the current draw is modest — typically 0.5–1.5A at 12V. At short run lengths (under 5 metres), 1.0mm² cable is adequate. At longer runs or where multiple fittings share a circuit, 1.5mm² is the safer specification.

The refit sequence that avoids problems:

1. Identify the circuit the fitting will connect to and confirm its breaker rating
2. Measure the cable run length from distribution panel to fitting
3. Calculate required cable cross-section based on current draw and run length
4. Confirm the cable entry position at the back of the fitting matches the installation point
5. Run and secure the cable before closing the headliner or joinery
6. Connect the fitting last, after the cable is in place and tested

Cable cross-section reference for LED yacht lights:

Pros of planning the cable run in advance

• Avoids undersized wiring that causes flicker and LED stress
• Allows correct fuse/breaker sizing at the panel
• Eliminates remedial work after joinery is closed
  

Cons of skipping this step

• Intermittent dimming and flicker that are difficult to diagnose
• Premature LED failure due to voltage drop
• Reopening headliner or joinery to upgrade cable �� the most avoidable refit cost

Refit Checklist

Work through these items in order before placing any orders.

Electrical System

• Confirm system voltage at installation point (12V or 24V DC)
• Confirm charging voltage peaks at installation point
• Specify only fittings with 10–30V DC input range, or confirmed single-voltage match
• Confirm breaker/fuse rating for each new circuit

IP Rating

• Map all installation positions and assign required IP rating to each
• IP65 minimum for all interior positions
• IP67 for companionway, cockpit, and wet area positions

Dimensions

• Measure existing cutout diameter/dimensions for all replacement positions
• Confirm new fitting cutout requirements from datasheet
• Check mounting depth against available clearance
• Confirm cable entry position and required clearance

Light Quality

• Select one colour temperature for the entire accommodation (recommend 2700K)
• Confirm CRI 90+ for all living space fittings
• Specify dimmable fittings for berths, saloons, and chart tables

Wiring

• Measure cable run length for each fitting
• Select cable cross-section based on current draw and run length
• Run and test cable before closing headliner or joinery

Design Consistency

• Select one fitting series for courtesy lights throughout the accommodation
• Confirm reading light series matches the interior hardware finish

Frequently Asked Questions

How long does a lighting refit take on a typical sailing yacht?

For a 40–50 foot yacht with a complete accommodation refit — replacing all reading lights, courtesy lights, and downlights — a professional installation team typically allocates two to four days. The majority of the time is cable running and making good the joinery, not the fitting installation itself. Planning the specification in advance (using the checklist above) reduces installation time by eliminating specification queries mid-project.

Can I mix LED brands during a refit, or should I use one supplier throughout?

Mixing brands within the same interior creates visible inconsistencies in colour temperature and CRI even if all products are nominally specified the same way. Two fittings both labelled “2700K CRI 90” from different manufacturers will often look different in side-by-side installation. Using a single range from one manufacturer — particularly for courtesy lights that appear in repeated positions — eliminates this risk.

Is it worth replacing halogen fittings that still work?

In most cases, yes. Modern marine LEDs consume 60–80% less power than the halogen equivalents they replace, which meaningfully reduces hotel load on the battery bank. On a boat that spends time at anchor without shore power, this extends usable time before needing to run the engine for charging. Additionally, the colour quality of a CRI 90+ warm white LED is equal to or better than halogen in most applications.

What is the most common mistake in a yacht lighting refit?

Buying the fittings before confirming the dimensions and voltage. The second most common is choosing 4000K or 5000K LEDs because they were cheaper or more available, and discovering after installation that the interior feels clinical rather than warm. Both errors require replacing the fittings to correct. The checklist above is designed specifically to prevent them.

Do I need to rewire for LED if I’m replacing halogen fittings?

In most cases, no. LED fittings draw significantly less current than halogen equivalents, so existing cable is generally adequate or oversized for the new load. The exception is if the existing wiring is corroded, undersized for the run length, or if you are increasing the number of fittings on a circuit. Check the existing cable condition at each installation point before reusing it.

Cabin Denmark has been designing and supplying marine lighting since 1977. Our team is available for specification questions on refit and new-build projects. Full product documentation, including datasheets and installation guidance, is available at cabindenmark.com.