Hello Jason,
The safest way would be to add navigation lights to your canoe. This would also make you "legal."
I would suggest a bow light like this from
Innovative Lighting. They also offer LED replacements for the bulb that will enhance battery run time. The clamp on the light is junk and I am not sure the suction cup is much better. The light is very simple and you should be able to come up with a way to mount it.
Instead of a stern light, I would suggest the rear paddler put
this in his hat as a marker light. It has a very useful clip and a velcro band that allows you to clip it or make a hat band to attach it. This will put the light at a higher elevation off the water and you have a better chance of being seen.
Now you need a main powerful light to read channel markers etc. I would suggest you look into some of the lights used for bicycles. They offer a weather resistant/proof halogen lamp with a rechargeable battery pack that can last quite a long time if you choose a lower powered lamp. Go for a spot beam rather than the flood beam. A recommendation would be something like the TurboCat S32 with NiMh battery pack.
View the S32 here This would give you a little over 3 hours on low (12 watts) or a little over 1 hour on high (32 watts). You might need to pick up an additional battery pack to last you through the whole race. Please note that this light would only be turned on when you have to find something in the dark. It would not be on all of the time. Also, you would have to come up with a way to mount the light on your boat.
Another alternitive would be the Underwater Kinetics SL6 or a Princeton Tech Surge. These are hand held lights.
That has the spot light requirement covered.
As for general lighting to check a map or to find the dropped candy bar, go with a headlamp like the Petzel Tikka + or similar.
Tom