When I was living aboard (Toronto winters). Some people would hang a 60 watt bulb and fixture next to each through hull to keep then nice and warm over the winter! I did this for a couple of winters and then realized that this technique wasn't necessary with the bubblers in our marina! The system they used had massive compressors and the entire slip would stay ice free.
Wow, that's a good idea. I wish I had thought about doing that in my Engine Compartment.
But, here in the US, I don't think they sell regular light bulbs anymore by law. All that you can buy anymore are CF, but I'm not 100% positive. But I think that is the way it is right now.