Hella Marine R10W Replacement Bulb, BA15s Base, 12V, 10W

Overview

The Hella Marine 178560021 is a 12V, 10W incandescent replacement bulb with a BA15s base for navigation and interior light fixtures that use a single-contact bayonet bulb. It is a straightforward swap when a light has gone dim, the filament has failed, or you are restocking spares for onboard lighting.

This is a standard filament bulb, so light output will typically fade over time as part of normal use. Keeping a spare on board makes sense for boats still running traditional incandescent nav lights or cabin fixtures, especially if you do night arrivals, early departures, or spend time at anchor after dark.

Key features

• 12V DC, 10W incandescent bulb for common onboard navigation and interior fixtures
• BA15s single-contact bayonet base for twist-lock style lamp holders
• Fits traditional housings where the bulb base is the deciding factor, not the fixture brand
• Useful as a spare for lights that matter underway, including nav lights and frequently used cabin lamps

Compatibility and fit

Match the base first: BA15s is a single-contact bayonet base, so it installs with a push and twist. Confirm your system voltage is 12V and that the existing bulb is rated 10W, since wattage affects heat inside the lens and housing. If your fixture is 24V or calls for a different wattage or base style, this is not the right bulb.

Installation and replacement

Switch the circuit off at the panel, open the lens, then remove the old bulb by pushing in and twisting to unlock. Seat the new bulb fully before twisting to lock, then close the lens and confirm the gasket is sitting correctly to keep spray and condensation out. After powering back up, verify the light comes on and stays steady when the boat is underway and vibrating.

Use on board

This bulb makes sense for owners keeping older incandescent navigation lights and interior lamps in service and wanting a known-fit replacement for BA15s holders. It is also a smart spare for coastal cruising, fishing trips, and any boat that relies on conventional bulbs for quick, simple repairs away from the dock.

Maintenance notes

If a bulb fails early, take a quick look at the contacts and socket condition. Corrosion or a loose holder can cause intermittent operation, especially in damp areas like the bow pulpit, transom, or an open cockpit light. Keeping the lens sealed and the socket clean goes a long way toward steady lighting.