You can find plenty of pictures from different races on Flickr including such ultra marathon events like Texas Water Safari, WaterTribe, Missouri River 340, or Yukon River Quest. There are posted in various paddling, kayaking or geographically oriented groups. I think it would be useful to gather all these pictures in one group and, perhaps, put more emphasis on different racing boats, their outfitting, paddles and other racing gear.

I have opened a new group on Flickr - Fitness Paddling and Racing

http://www.flickr.com/groups/fitness-paddling-racing/

So, if you are already on Flickr please sent your pictures to my group. If you are not, it is easy to join. A free Flickr account will allow you to upload up 100 Mb of pictures per month. It's a lot, especially, if you downsize your pictures before uploading.