[deniseO30]

Not many 30 ft boats can be on a trailer.. at least not the type cars pull. From around 26ft up most are lifted in slings to and from the water. Or some yards use a hydraulic trailer. Boats need insurance!

 

[deniseO30]

The reason larger boats are not towed behind personal vehicles is beam (width) and horsepower to move 8-10,000 lbs of weight.
Towing a Big Boat on the Road? BoatUS Trailering Club Offers Discount Wide-Load Permit Service : BoatUS Press Room

J/30 certainly doesn't seem to be "trailer-able" What's a "ULDBs".?

Unless you are looking at Marine facilities that do not have yard storage you will never need or want a trailer. this is what/ how it's done at most marine yards. (sales promo, No involvement on my part)

 

[deniseO30]

Ultra Light Displacement Boat

Oh! But still heavy for towing?