Well, the wind in Southern Florida has been relentless and seemingly never ending this winter. After bouncing off the post in our fixed dock aligned against one post, I solved the problem. We couldn't get any fender to fit properly and stay there.
I pulled out my EasyStow Inflatable Fender. We happen to have the 44 Inch long, 18 inch around standard model. A few quick pumps from their inflation pump and we were ready to hang it lengthwise between rail stanchions.
I am continually amazed at how simple yet tough these fenders are. I did steal a couple of pillow sheets and sacrifice them to keep the "squeaking" noise from fiberglass boat to wood to fender.
They sell covers but I neglected to order them when I ordered the fenders. Problem solved!