As I've mentioned in the past we had our GB36 trucked from Alameda, CA to Tacoma, WA in 1998. We used one of the best marine trucking companies in the west, at least, although they may cover the rest of the country as well. The company is Associated Trucking. They, and I'm sure other marine haulers, use a special trailer that drops the forefoot of the hull almost to the pavement. This reduces the overall height of the load.
Another company I have heard good things about which is also based out here is Dudley. But a number of experienced GB owners on the GB forum seem to agree that Associated is the one to use if they serve the area you want to move a boat in.
At the time we did this Associated told us that a GB36 was the largest GB they could haul without removing the flying bridge. Anything larger and the flying bridge had to come off and then of course be put back on again, both time-consuming operations which means expensive.
They also said we were lucky in that being out west, the bridge clearances on the roads tend to be higher than many clearances back east where a lot of the overpasses are much older and so can be considerably lower. As it was they did not want to truck the boat any farther north than Tacoma because they said that there were some real iffy clearances on some of the I-5 overpasses in the Seattle area.
The cost for the trip back then was about $4,0000 which was about what it would have cost to have a delivery skipper run it up the coast for us. The truck trip took only three days including loading and unloading. A pilot car was required. And our insurance company was a lot happier with the boat on a truck for that journey instead of out at sea off the west coast.
For a local haul from the water to a nearby piece of property the cost should be much less, although unless there is a marine hauler in your area you may have to pay for one to come to you and then return to base.
While I know little about the art of hauling a boat I am pretty confident from our own experience and from the boats on trucks I see on I-5 and coming to the Seaview North yard in Bellingham that you don't want to turn this job over to just anybody with a truck and lowboy trailer. Smarter, I think, to hire a firm that does this kind of thing for a living and has an extablished repuation for being good at it.