Since lights are being discussed I thought that I'd share some things that Joey and I have learned.
One thing that I see a lot is that new guys tend to put the cart before the horse. By this I mean that they often have a perception of what kayak fishing is and try to prepare for their preconceived ideas. The reality is often very different. Some stuff isn't going to be learned until you have a yak. Lighting is one such thing.
I don't use front and rear running lights. I'm not a boat and I don't want boats to think that I am. The places that I fish at night with a kayak are places where boats won't venture during the day, let alone at night. The lack of speed and often movement of a kayak might make a boat think that you're a buoy or something stationary and might actually put them in jeopardy. Also I only use a light when I need to, otherwise it ruins my night vision, and it spooks the bass.
I carry a waterproof headlamp which I put on my ballcap. I also carry a 360 degree light that's designed to be seen a couple of miles. I put this in the elastic of my headlamp when I want to be seen. Most of the time I don't. The last item is a red flasher. these can be seen from miles away and are a good item to have. When JOey and I fish at night often we go off in different directions at times for various reasons. Its wasy to know where the other guys you're fishing with are when they have a flashing red Led.