I knew how I wanted to do the pole itself, and want it to be truly portable, so wanted a battery based light, but one I wouldn't have to replace every time I dropped it in the water.
At the suggestion of some great person on the 'net, I got the Fantasea Nano Spotter light from B&H photo (http://www.bhphotovideo.com/c/product/527259-REG/Fantasea_Line_6023_Nano_Spotter.html). I can't remember what forum had someone share the link, but appreciate whoever/wherever it was.
Nice things about it: It's got bright LEDs, is truly waterproof for my purposes, and it has the diffuser already.
Minuses - the base is not round.
That's not really a problem, though. I took 3/4" PVC and heat gun. I wrapped two or three wraps of electical tape around it before forming the pipe with the light, so it would be tight but not impossible to remove. Heat PVC, smoosh, let cool, pull out the light, dunk in a bucket to "set" the shape.While I was at it, I made two. I then cut the formed piece off and sanded any roughness from the heat off, along with the lettering.
Once glued into a slip/female thread coupler that attaches to the top of my 3/4" light pole with a matching male thread. I painted the whole light pole black. I actually wish I hadn't painted it, but I got PVC solvent all over it, and didn't like the purple streaks. I plan on using reflective tape bands around it anyhow.
I sprayed liquid electrical tape inside, so the light press fits in. If it seems at risk of falling out, I'll probably add a hole big enough for the lanyard strap, and use a toggle or something.
One thing I thought of doing was using a tee at the top, having one light shining up, one forward --maybe even without the diffuser.
The photo is the spare I made, and may use for the forward facing light. I'll get a picture of it on the kayak sometime.
