The fact that Alton has built in NC (and sees that Miami is falling off) and knows that there are still fine craftmen up there has to be part of the equation. Also, if he's a savvy businessman, he is working out incentives from the local cities, counties and state that will make it very attractive to move there.
And I agree that the FL counties are helping to drive boat businesses out of the area. Broward is also on the list of declining builders and yards. But I hear that Charleston is picking up as well as other areas up north, out of Florida (except for Rybo perhaps).