Posting for a friend because I want to know other's opinions and tho' I'm a very good and very experienced maintenance/handy man I'm still not an electrician.
I live on a lake and most of the floating docks here are wired for electric lights, air pumps for floating boat lifts, and usually a provision for battery chargers. Also, many docks will have well pumps to use the lake water for washing down boats. Generally a boat dock will have 2 to 6 outlets and a couple of 8 ft florescent light fixtures and maybe some kind of light out over the water. The distance to the main switch box in a lake house is typically 200 ft from the dock.
Generally the docks are wired with 12/2 WG in conduit. Also, if the ground comes from the switch box rather than a ground rod at the walkway to the dock you can get a 6 to 8 volt "tickle" when you climb upon a metal boat dock... So, I've installed several ground rods at the walk way and cut the safety ground from the switch box to stop this "tickle" voltage which is a result of voltage drop from the long distance of wiring to the dock. A typical walkway to the dock is 65 ft.
Here's some questions... what size/type of wire would you run to the dock?
Would you use a GFCI breaker, GFCI outlets, or both?