Another option is an equipment trailer. Something like this:
Bobcat Trailer - Load Trail - Built for the Long Haul
Your boat might be able to fit on a 10,000lb trailer but it is better to go larger. If your tow vehicle is limited to 10,000lb or if like me you want to avoid the extra expense and hassle of a trailer registered for more than 10,000lbs you can get the trailer rated and registered for 10,000lbs.
I did this when I couldn't find a suitable boat trailer. It means you will need a cradle which varies in price from nothing (if you build trailers as in one example) to $1G at most. You can then strap or bolt the cradle to the deck.
It worked out very well for me as I shopped hard for the best price on the trailer and ended up selling it for what I paid for it, maybe more if you ignore the cost of taxes (as so many do) and consider it had a couple years of wear on it.
Sure was a nice tow, down right comfortable with the trailer not being overloaded, well built, and everything brand new.
I would do it again but my current boat would be over height on a flat deck, then again it is cheaper than a boat trailer and much easier to sell when the time comes. A boat trailer can take weeks to sell, a like new equipment trailer will sell same day posted.
If you consider buying used then now is the time, lots of equipment trailers out there but lots of trouble with them too.
Edit: On a second look that one is different than the one I had. I think the model I had was called a car hauler, same idea though.