I've sailed forever (it seems) including tons of offshore racing where you are constantly shining tell tales and windexs so you can optimize sail trim.
What you DON"T want is a light that is too bright - with reflectivity of light colored sails, deck and spars you will totally destroy your night vision - I mean totally. When that happens, you are in trouble for boat handling at night until your night vision returns.
The Windex is reflective and it has relective patches on the tip and tail of the thing. ANY light will light it up enough to be seen. I would suggest something that is LED based but not particularily bright. You don't want a tight spot focused beam because it is hard to aim at such a small target on a pitching boat at night. I would suggest something like a Inova X5 with red LEDs, the Innova 24/7 using the red lights. These would more than competently light up the windex and NOT wreck your night vision.
My all around favorite for sailing lights if budget is not an issue is a Surefire A2 with RED LEDs. I always carry one with me when sailing at night.
I am able to light up the reflective patches on my sailboat from shore (I live on a large body of water) that is almost 75 yards away. I can do that easily with the RED leds on my A2. Even though you cannot see it on anything else at that distance, you CAN easily see it on the reflective tape especially once your eyes are dark adapted. Try this for yourself with a cheap 2 or 3 LED light.
The A2 also has a tightly focused spot for finding buoys and nav marks at long ranges without a lot of side spill to ruin your night vision.,
Because of the high reflectivity of the windex and presuming you are night adapted, you could probably use almost any 1 (overdriven) to 3 (underdriven) LED for night sailing. I would opt for more LEDs and then get them in red.
I also own a variety of Surefire lights like the 6P, two Aviators, etc... The P60 beam is TOO BRIGHT for this application. The only counter to this would be to use a red filter but that isn't all that much brighter at a much higher battery consumption than using a Red LED based light.
J
