Bulbs

The right spare bulb turns a dark passage back into a lit one. This collection covers replacement bulbs for every light on board: navigation light bulbs in the correct wattages, festoon, bayonet (BA15/BA9) and wedge fittings for cabin and courtesy lights, instrument bulbs, and LED replacements that slash power draw in 12V and 24V systems.

Two things matter when replacing a bulb: the fitting (measure or match the base type) and, for navigation lights, the wattage - nav light certification depends on the specified bulb, so replace like for like. LED upgrades are excellent for cabin lighting, cutting consumption by around 90%, but for navigation lights choose purpose-certified LED fittings rather than dropping LED bulbs into filament housings. Keep a labelled box of spares aboard; bulbs always fail at night.

Frequently asked questions

Can I put an LED bulb in my navigation light?

It's not recommended - navigation lights are certified as a complete unit with a specified filament bulb, and an LED insert can change the visibility range and light pattern. For LED nav lights, fit a certified LED fixture.

What are the common bulb fittings on boats?

Festoon (tube with pointed ends), bayonet BA15d/BA15s and BA9s, and wedge W5W fittings cover most cabin, courtesy and navigation lights - match the base type and voltage when replacing.

Are LED bulbs worth it for cabin lights?

Yes - LED replacements draw around a tenth of the power of filament bulbs, run cooler and last far longer, which makes a real difference to battery life at anchor.

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