The Dual-Contact Bayonet Bulb – BA15D Round Globe is a clear-glass replacement lamp for compatible marine light fittings that use a BA15D double-contact bayonet socket. It is offered in 12V or 24V versions, so the selected option must match the vessel’s DC electrical system. The supplied product image shows a compact, clear bulb with a visible filament and a metal bayonet cap, suitable as a replacement where the existing fitting requires the same lamp form and electrical connection.

BA15D describes the bulb base rather than its light output. “BA15” identifies a 15 mm bayonet cap, while the “d” identifies two contacts on the bottom of the base. The side lugs locate in the matching holder and lock with a push-and-twist fitting. BA15D bases use level, in-line side lugs, so this bulb should not be substituted for a different 15 mm bayonet pattern such as BAY15D, which uses offset lugs. Checking the old bulb and holder before ordering is important for correct fitment.

For marine use, this BA15D bulb can serve as a replacement navigation light bulb, anchor light bulb, or general boat light bulb when the lantern or fitting is designed for this base, voltage, bulb size, and output. It may be used in selected navigation-light housings, signal lights, indicator lamps, cabin fittings, and other onboard light fixtures. BA15D double-contact bases are also used in marine navigation lamp products and replacement bulbs.

The final use depends on the equipment manufacturer’s required lamp type and the colour of the lens or the optical design of the fitting. A clear bulb does not itself determine a navigation-light colour; the complete light fitting, lens, and bulb combination must match the vessel’s installation requirements. This makes it important to replace the bulb with the same base type, voltage rating, and suitable specifications required by the existing marine light.

The dual-contact design delivers the electrical connection through two contacts at the bottom of the base, while the bayonet shell is retained mechanically by the socket. This compact connection style is commonly used in specialty, vehicle, and marine-lighting applications. Its push-and-twist fitting is practical for routine replacement when the holder is accessible. Before installation, isolate the relevant circuit, allow the fitting to cool, and avoid touching the glass unnecessarily.

Select the 12V version for a compatible 12V boat electrical system or the 24V version for a compatible 24V system. These should be treated as voltage-specific alternatives, not as one bulb intended to run across both systems unless its label specifically states a wider voltage range. Wattage, brightness, filament design, bulb dimensions, exact globe shape, light colour, IP rating, and certifications were not supplied, so confirm these details from the product label or the old bulb before purchase.

This BA15D bulb is a practical service part for boat owners, marine technicians, electricians, and maintenance teams restoring a compatible fixture. It is particularly useful in established installations that are not designed for wedge-base, screw-base, or LED retrofit bulbs. For buyers searching for marine navigation light bulbs, a boat navigation light bulb, or an anchor light bulb, the key compatibility check is the socket: this product fits a BA15D double-contact bayonet holder only.

Key Features:

• Clear-glass, filament-style replacement bulb as shown in the supplied image.
• BA15D double-contact bayonet base with a nominal 15 mm cap diameter.
• Two bottom electrical contacts and two level side lugs for push-and-twist fitting in a matching BA15D socket.
• Available in 12V or 24V versions; select the variant matching the vessel’s DC system.
• Compact replacement option for compatible marine lights and selected onboard fixtures.
• Suitable for fittings that specifically require a BA15D bulb.
• Not interchangeable with all 15 mm bayonet bulbs, including offset-pin BAY15D types.
• No wattage, lumen output, colour temperature, dimensions, IP rating, or certification is stated; verify the required specification before ordering.

Applications / Suitable For:

• Compatible boat navigation light fittings using a BA15D double-contact bayonet holder.
• Anchor, mast, stern, port, or starboard light assemblies only where the fixture specifies a BA15D lamp with the required voltage and optical configuration.
• Marine signal, marker, and indicator fixtures with a matching BA15D socket.
• Cabin, utility, or equipment lights on boats, yachts, workboats, and other vessels where the original lamp has the same base.
• Marine maintenance inventories and onboard spare-bulb kits for vessels using 12V or 24V BA15D lamps.
• Non-marine specialty light fittings when their socket, voltage, and bulb requirements exactly match.

FAQs:

Q: What does BA15D mean?
A: BA15D identifies a 15 mm double-contact bayonet bulb base. It has two bottom contacts and level side lugs that lock into a compatible BA15D socket.

Q: Is this bulb suitable for a boat navigation light?
A: It can be used only when your navigation-light fitting specifies a BA15D bulb and the selected 12V or 24V version matches the vessel’s system and fixture requirements.

Q: Can a BA15D bulb replace a BAY15D bulb?
A: No. Both are 15 mm double-contact bayonet styles, but their side-pin positions differ. Compare the old bulb and socket before ordering.

Q: Is one bulb suitable for both 12V and 24V?
A: Select the voltage-specific version for your system. Treat 12V and 24V as separate options unless the actual bulb label states a wider voltage range.