I am getting confused. What is the legal way to haul a boat in State/ out of State/ over so many hours.

For example if i tow a 50' with a dually from NC to Texas what do i need to stay away from the blue lights.

with a dually??? I would imagine nothing. your pulling a boat with a pickup. non commercial.

if you are doing your own private vehicle you can drive as long as you want unless you become impaired. but otherwise you are exempt from cdl hours of service rules

The only thing i know of when towing your own private boat is to stay with in the GVWR rating of your license....i know a few guys here in IL that got busted for towing their race cars home by the State police.
In IL the standard drivers license is 16000lbs and below.....these guys were towing over size enclosed car trailers with crewcab duallys....combined weight was over 16k lbs and got busted for it......they all got lucky as the cop didnt show up for court but i dont know if this would have got thrown out or not considering they are not comercial drivers.....
Another thing to check is oversize restrictions from state to state....i dont think you can tow anything legaly over 8'6" wide unless you get a permit to do so...i may be wrong on that but the state dont care about ignorance

50ft boat behind a dually need to worried about over length I think

I don't know of many 50' boats that fall with in the constraints of towing capacity of any traditional 1-ton dually.

What are you thinking about towing and what are you thinking of towing it with?

Semi tractors pull 53' trailers, I would think he is ok.

Right, but they have 10+/- feet hanging over the top of the tractor which is 25 feet long or so.

If he is pulling a 50' boat with drives hanging off adding another 3' feet or so, and a trailer tongue of some sort; its conceivable to have a boat/trailer setup that is at least 56' long.

A typical crew cab long bed dually is 21' or 22' long. Most states have an overall length limit of 65 or 70 feet. Overall length ads up pretty fast in that case.

Pull the dam thing just don't get over tired. Obey speed limits and use common sense. Most and I say most officers want to stare at the boat and wish but god help you if you screw up

Don't have any company lettering on the truck (even if landscaping, painting, electrical etc.) then you become a commercial tow vehicle and the laws change from personal use.

What are you planning on pulling anyways??