Over the last few months I have been out during the early hours 2 or 3 am in a boat.
I can tell you for sure that the kayaks are hard to spot even with a light, and I'm looking closely for them and know where you would be fishing.
I use this light from WestMarine because it shines 360 deg. and does not ruin your night vision.
-I clip it on the
Top of a rods for maximum visibility.
http://www.westmarine.com/webapp/wcs...classNum=11075