No. You will have to physically disconnect the flex and the wires when you are ready to move the dock. You also must have a disconnect where the new circuit starts. I would replace the existing receptacle and mount a small weather tight disco. You could use a 4x4 treated post and install the disco and receptacle on it. It would be easy to un-install the flex and wires from a disconnect. Since the circuit is protected by a GFCI breaker no other GFCI is required.I need to run service for receptacle to my dock on the lake. the dck is taken odd the water for the winter, so I would like to be able to disconnect without messing with a junction box. I have a receptacle 6-8 feet from the dock with GFCI upstream. I was thinking about running a liquid tight conduit properly strapped with heavy nylon ties on the inside of one of the dock aluminum trusses
No. Use straps listed for the conduit. Ty raps are not allowed. I would use PVC, not flex. You can use flex where the dock moves.
and flex it up to one of the posts/legs and finish it wirh a water tight device box.
Come up under the dock roof. Attach the weather proof box to the truss there. (convenient).
On the land end I would like to run the flex loose on the ground under a 4' connecting ramp and plug it to a receptacle.
Not on the ground. Attach it to the under side of the ramp.
Does this seem like an acceptable solution?
This is really not a good DIY project unless you promise to get it permitted and inspected. Death or serious bodily injury may result.
The AHJ will have special requirements. He is who you should direct your questions too. No two inspectors will have the same opinion on this project. Or hire a licensed electrician to do it.
Are there terminating plugs for flex conduit? If not can I terminate it on a "loose" box and run a pig tail out of it?
Check around and see what others on the lake have done in this regard. To give you an idea how others have done it. Ask if it was performed by a licensed electrician or contractor.