Sorry to sound flippant jaxs. I asked an honest question. Perhaps the only honest answer in 25 words or less is to 'hire out a builder with dock building experience'.
As for other experience, I spent 5 years doing manual labor until I graduated from HS, then running a printing operation while in college, then accounting (Controller) for a large chemical manufacturer. Final 12 years in project management for a NASA subcontractor.
Hobby experience for the entire time was in auto mechanics and woodworking. Yes, I have a substantial knowledge of woodworking, having grown up with a father that also spent 40+ years as a union carpenter. I do have a nice array of woodworking tools to go along with a lot of woodworking experience. (None of which entails dock building!)
That said, and me being well past 80, perhaps the "honest answer" is the right answer?