First off - I love the initial design.
Next, intended usage? Is this boat going to be an every (or every other) weekend boat that you tow to the launch point and then back home again?
I ask because of the total beam. At 8'6" (2590mm) you are indeed at the max legal - without a permit towing width in most states. Some states have a max legal width of 8' (2438mm).
But, in all but 3 or 4 states - can't remember exactly which right now - a private individual can to up to about 10'6" (3200mm) wide without a pilot car. Yes, you do have to have overwidth signs, and in some states flashing lights, and yes, you do have to have a permit. The permit as best I could research runs from $25 to $75 depending on the state. And yes, it's usually a one time trip and yes, you need another permit for the return trip.
My point? In a boat that is going to be used for a long-ish trip to The Bahamas during the winter - say 2 to 4 months - the boat could easily be towed behind a HD Pickup and the hassle/cost of the trip permits would be but a small part of the overall trip.
But if you are intending to frequently tow the boat for quick get-aways, then the hassle of a trip permit each time would outweigh the benefit of that extra 18"-24" of beam.
My thinking is that I want a retirement boat in the 9 (29.5') to 9.5 (31') meter range with the beam about 3m (9'10").
Usage would be as before - long-ish trips and not very frequent trailering episodes - say at most 3 round-trips per year.
Winter in The Bahamas - Summer in Maine as one example. How about Winter in the Sea of Cortez and Summer in Alaska as another?
In my research the only "absolute" that I've found (and it isn't really an absolute as there are ways around this) is the total height on the trailer. Interstate Highway System minimums are set at 13'6" (4114mm).
So doing the numbers, I've figured that the total height of the boat, from keel to the highest point when ready to trailer is about 3500mm, (11'6").
That leaves about 600mm (24") for the trailer axles and the trailer frame. That's reasonable if the trailer uses a dropped axle. Not if one specs a straight axle.
So Garry, just curious 'ya know, what's this design going to measure out when sitting on a trailer?
Best,
Leo