If what you're looking for isn't on the sale section here, check on the Colorado Western Slope craigslist, and then try checking on Rivertrader-dot-com and also with the Grand Canyon Private Boaters list (gcpba-dot-org) and Utahrafters-dot-org.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse