how are you going to ensure you dont get any on the gelcoat? it seems that it would be painstakingly slow going through and being OCD about where you get the product and where you dont.
ive had pretty good luck just using regular mildew spray, scrub with a soft brush, and rinse right away.
by sea or land?
if by sea, try Will with Captains Coach. he does yacht delivery professionally (as well as training). As a bonus, he documents everything on a youtube channel so you would get to see the journey as well.
i got mine from Atlantic Coastal Welding in NJ. they did a great job. they do a lot of shipping. when i was there, they had some going to the west coast, and i think one to hawaii