The Navigation Rules are available here:
http://www.navcen.uscg.gov/mwv/navrules/navrules.htm
However, they're pretty hard reading - the short version is that a vessel with paddles or oars is only required to have a flashlight or lantern that they show in adequate time to avoid collision.
If they do show a light, they need to show the same lights as a sailing or small power vessel - red and green side lights and a white stern light when underway, white all-around when anchored.
You can buy battery-powered lights with suction cups for kayaks, but they're just 2D flashlights with a divided red/green filter in the right shape - way better than nothing, but not great.
At the very least, I'd have a Pelican or other very narrow-beam flashlight on board, to display when a boat is in sight, an Inova 24/7 for a beacon, and something else (not quite sure what) for a white all-around light to keep on all the time.
Glo-Toob or similar isn't really bright enough - depending on where they are, they could have bass boats or other high-speed craft coming through, and they need at least a mile of clear visibility for safety... an underpowered Luxeon in some kind of all-around fitting would be good, but I don't know of any.
BTW - high-intensity Strobes are emergency beacons - and a user of this as a marker won't make any friends when somebody reports it and the Coast Guard Helicopter comes to rescue you...