I have been doing quite a bit of night sailing this summer. The nice warm summer nights have been so inviting. I usually go out before sunset to witness the end of another perfect day. During my nightly cruises I was noticing the big drawn down of my battery due to the standard bulbs in my running lights.
The original bulbs were rated at 8 watt at 12 volts. There are two bulbs in the bow for the red and green navigation lights. Another one for the white stern light. If I ran the masthead light too, that was a total of 32 watts or about 2.67 amps.
The existing Perko running lights on the S2 6.9 use what is called a festoon bulb. They look like a barrel with the connections on each end. These existing 8 watt bulbs are about 1.25 inches long. Make sure you get the right size. You can go to any auto parts store and buy a pair for about $6-7 bucks.
I wanted to replace mine with LED lights so I went to my trusted source Amazon.com. I do all my shopping there. Sure enough, I came across some 1.25 inch (31mm) festoon LED dome light bulbs. These were even cheaper than the standard bulbs that I saw at the auto parts store. I purchased the four pack for $6.49 plus free shipping, what a deal! They have 12 LEDs so they very bright.
They were simple to replace and they fit perfectly into the existing fixture without any modifications. Project done, and think of the amps I will be saving every time I go night sailing.
I could not find a wattage rating on the package so I do not know for sure how much energy they draw. It is probably in the range of a few watts a piece, significantly less than the 32 watts I was using. They are not marine rated so saltwater or moisture may affect them after a few years. At that price, I really don't care. They should last a very long time and save me many amp hours of battery use.
Pick some up yourself and get out and do some night sailing!