My experience with the C Dory 25: I had purchased the boat in New Jersey and taken it to my home in Florida. I kept there for about 8 months, thinking I was clear of sales tax in Calif. But the law had been changed from a year out to state to 6 months out of state, after I bought the boat--so Calif. said I fell under the old law of a year. Got you! Fortunately the Franchise Tax Board accepted the price I paid because the boat was damaged.
I put the boat in dry storage in San Juan Capistrano, near where my son lives. The boat was federally documented. Every storage lot, marina etc has to report every boat to the county tax office. The date is Jan 1, 12:01AM, for boats Based in Calif. (even though you remove the boat on Dec 30, and return it on Jan 2, it is still taxed, if it is "based" there more than 6 months a year. I got a bill at my home in Florida based a value of $60,000. Remember the boat is documented with hailing port of Pensacola, FL. I protested that, and submitted that Franchise Tax Board had accepted my cost of $30,000. DENIED: The Orange Co. Tax collector said that most C Dory 25's of my vintage sold for $60,000, and since I had "fixed the damage" it was worth that.
An aside: I had purchased a 62 footer and took delivery offshore of Calif. The boat was then docked in Mexico for 6 months, before I brought her to Calif. for outfitting before we went cruising for 4 years. She was documented out of Mississippi. Almost immediately when we returned to Calif. I was hit with a tax bill of over $30,000. (Sales tax, property tax, and penalties). I was only able to get those canceled, after a notarized statement from the Yacht broker, copies of the slip rent in Mexico, a copy of my entire ship's log, and copies of every page of our passports for 4 years) Your boat remains on the Calif. tax roles when cruising, unless you establish a "permanent" moorage port outside of California!
(An aside, I as charged a tax on the land under my slip in Long Beach, even though that marina was owned by the city of Long Beach!--as well as paying $16 a foot a month for the lease fee).
Yes, the slip fees and maybe even dry storage may cost more than driving to and from Las Vegas. With a Tom Cat, probably the mileage will be 10 mpg, or less for the diesel truck.
As for Powell, vs Mead--no comparison--Powell is a far better place and I have boated on both a number of times. I had not looked at it as a "savings" going to Powell, but an additional place to boat and fish.
Will you catch as many fish with your own boat as on a charter boat? I don't know. but you have to ask that question. There are hidden costs of boat ownership--if you pay cash, the loss of that $80,000 to $150,000 of your money working for you ( at 5% to 7%), of you borrow the money--the interest you pay. The cost of fuel, at 2 miles per gallon or less (the Tom Cat is economical for the size of boat--most will be 1.5 miles per gallon.
The costs of engine maintenance, (oil, lube, impeller changes, wash and wax after each use, repair of things that break, etc.) When you eventually put the boat in the water there are the slip fees, diver fee for cleaning the bottom, bottom paint (with epoxy barrier coat). All of these are "cost of ownership".
Even if you "move" to San Diego, you may want to keep residence in Nevada, and stay there one day more than 6 months out of the year for income tax, car tax, Personal Property Tax, insurance etc...I am sure you know people who do that...
My experience is from having living and boated in S. Cal about 50 years, but when retiring in 1992, the first thing I did was to establish residency out of Calif.