Yes, been there 20 yrs ago on a regular dam release. A bomb proof big water roll is a very good asset; that is a must have. You should be able to roll in Norman's or Coli any time!
I found this link a year or so ago for the turbine test releases, would be interesting to see how big that is!
http://www.northernoutdoors.com/site/rafting/kennebec-river/turbine-test-releases.htmlThe stretch that we paddled was 12miles, with a 4 mile canyon at the start right from the dam. On a regular release, the canyon starts with class 2 or 3- for the first 1.5 miles then the pitch changes, creating a wave that was called Big Momma and the big hay stacks start and continue for 2.5 miles, one person swam this and was not happy! With the long boats there were many waves that could be surfed, if not chasing boats and gear through the hay stacks, but I don't know how short boats would be. There are a few more 3+ or maybe one 4 rapid which I don't remember much of. The last probably 4 miles was very fast flowing, basically a float to the takeout.
With some research and an organized shuttle, one might be able to run the canyon twice in a day if taking out above the float part.
I am looking forward to going there again one of these summers.
Bruce.