Or other thing is if the boat came from a pro its no longer a new boat worth 60k. It has depreciated over the year the pro had it so you would be taxed at the fair market value of the boat. Besides you could alway sell the boat cover the taxes then buy a modest boat free and clear. How much is a beat up pro boat selling for ? . Even if its a brand new boat nothing says you can't sell it for enough to buy a modest boat and still pay off the taxes.
I do like the guiding idea, and I do not believe that you would have to do it full time to take the deductions. As always, consult a tax professsional.