There are rental kayaks stored on the lake here. The sun accelerates fading and deterioration of soft materials (seats, bungees). Over time marine life attaches to the hull (slime, algae, etc) which degrades the performance of the boats. You would also need to check for water intrusion from rain, etc. before using. All and all I wouldn't recommend it unless there was no reasonable alternative and you were willing to inspect the boat carefully before each use.
If you had a way to store it off the water, covered, that would be much better -- or perhaps on a rack behind a building (cabled for security). It would be easy to wheel to the water without lifting the entire boat. Even with a nominal fee, you would probably come out ahead in the long run. There are marinas in this area that have racks and/or stand-up storage available for those who want to keep their boats at the water. You might check with the owner about the possibilities. If not, what about a dockside cradle for easy mounting, dismounting and sliding it out of the water? Here are some ideas:
http://www.kayakcradle.com/products.php
http://www.kayakdock.com/
http://www.ezdocktexas.com/floating-doc ... craft.html
http://www.ezdocktexas.com/floating-doc ... docks.html
