Here in Colorado, it is easy. We only title the trailer and not the boat (I find that odd because the value is in the boat.) Boat reg is $18 and all they wanted to know was fuel, hull length and material. So my boat reg says it's a 14' Steel hull, in-board gas powered boat. I did not mention it's automotive side to the boat people and did not mention it's aquadic side to the car people. They all know of me now!
The 1st time at a local state park lake, the lady at the booth just kept repeating "This is highly unusual... This is highly unusual..." and she had to call her supervisor for advice. She did not know how to charge me for a boat w/o a parking pass for the trailer. The state parks I use here now have provisions for my Amphi. Now, most of the time they just wave me by and smile.
Some states are just easier than others.
John "highly unusual" Bevins
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