Thanks for your comments, all.

Noah, eye bolts would solve the problem of hinge wear being hidden. I
hadn't thought of that. I will be using an engineer. Just wanted to get a
head start with some NG research.

John, you are a funny guy. Would be a perfect place for a party if you're
into rockin' and rollin'! Actually, the worst of the weather only happens
occasionally in winter storms, but it is a year-round dock.

Carolyn, yes, I have been called egocentric before! However, the dock did
beat nature for 15 years, and I'm aiming for 25 years this time. Check back
with me in 2028, OK?

One other idea that came up is to use heavy duty (Class 4) trailer hitches
at the float end of the stiff arms. These have a little give-and-take, but
I think you can get them with built in shock absorbers. Anybody actually
done something like this?

Pete