RAH, I have a combo dock too and think it turned out well. I along with help of three teenage grandsons built the 80'x 8' wide fixed section out of 8" "I" beam sitting on 12" diameter "osage orange hedge" posts. We also built the 8' long ramp portion and added one float under it.
The floating portion was bought off Craig's list. We made a metal frame for underneath it and used hinges for the floating and rigid parts that were planter market hinges out of the salvage pile.
I'm a lot better with metal than wood, thus the use of the metal sub-structure. I thought the floating part might need cables to stabilize it, but with the 8' wide ramp, heavy greaseable hinges, and overbuilt by several magnitudes (one of my shortcomings) there appears no need for the cables.
Sorry for the distant pictures. Not where I can take more right now and any other pics I have of the building process are on another computer I don't have access to right now.
Pond is 3.1 acres for size reference. Some pictures show pond about a foot below full pool. The slope of the 8' ramp drops about 8" over an 8' span when the pond is at full pool. Ramp is basically straight across to floating portion if 8" overflow pipe is running full bore. First picture is within a few inches of pond full pool.
Edit 2017. Since the pictures the overflow pipe was raised. At full pool the water comes to within a couple inches of the bottom of the metal tabs where the posts attaches to the channel. The floating dock sits at the same level as the fixed dock at full pool. When water is running out the overflow the floating dock will actually be slightly above the fixed dock. I like it much better since we raised the water level.
