Around here (Oriental) most docks are fixed. A few float. I use Tideminders, and have pilings that go up about 10' above average water level. I'm pretty pleased with the way they work. I use them on all four corners of my cat.

I have a fixed kayak dock, on small pilings manually driven into the ground "about far enough." It's been though several storms and water level changes, but this one caused it to float up, pulling the pilings out of the ground. I awoke to find my little dock and canoe gone... vanished! Upon looking around, found it on the opposite side of the creek, (only about 100 feet away) canoe still tied up, both floating happily. The wind was generally from the north, but the dock drifted directly northward. Go figure. Four fenders that were sitting on my bigger dock (the deck of which was underwater on Sunday) also crossed the creak, nicely tucked into the weeds.

With some paddling in a very small kayak (that could be worked into the 25 knot winds pretty easily), I managed to get my stuff back on my side of the creak.

Strangely, I found the paddling invigorating, so after rescuing my stuff, I paddled up the creak into driving rain while all suited up in waders rain coat, etc. Anyone watching would have to wonder if I should be committed.