-- Last Updated: Sep-20-12 9:44 AM EST --
The best loaner boat is your own beginner boat. I kept my first, very docile, sea kayak and it is a perfect boat to put rank newbies in, and I still enjoy giving it a ride once in a while.
PS - used composite is a great way to go - there's a used Pachena in the p-net classifieds that would fit the bill very well, although it may not be anywhere near you.