The Deck Light Fixture original bulb is incandescent 20W Bulb with GX 5.3 Base. This means that it has 2 strait pins that are about 1/16" in diameter.
In my images they are broken and missing.
The replacement bulb is available from Home Depot fro $6.97. It is not polarity sensitive. I tested with the engine running which increases the DC voltage to 14.6 Volts and it worked fine.The base is listed as GU5.3 - but is the same base. Unfortunately I was pressed for time and did not take photos of the LED Bulb.
The illumination at night is good as well.
To install - simply open the small door below the fixture and pull out the old bulb and insert the new one. I was surprised that there was no protective lens on the door.
Please let me know if it helped you by commenting below
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Model number is Hella Marine 8505. The new version is Hella Marine 8504, Visit this page

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