Largest trailerable sailboat
Have you considered folding multihulls? If your budget will allow Corsair Marine makes some very fun boats that will suit your needs well. We have a Corsair 31. 31 feet long, 22.5 foot sailing beam 8.5 foot trailering beam. The weight of the boat, gear and trailer is around 5000 lbs for our boat. The boat can be folded in a matter of minutes and getting the boat from the road to sailing can take as little as 30 minutes. The trampolines are much more comfortable and spacious than many cockpits...
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They currently make a 24, 28, 31 and 36. All can be trailered easily, the 36 may require permits as its trailering beam is wider.