Never used anything like this for a boat or anything that large but I've used the stuff on ATVs and snowmobiles... generally speaking they work great, just make sure to use the instructions to the T... if they say to treat the surface a specific way do it exactly how they say. I was surprised how well it's held up to scratches, bumps and bangs which was my main concern at first.
I only had an issue once with a snowmobile wrap. The vinyl started coming right off. Called customer service and they had me send a digital picture. I guess they thought I was scamming them which tells me they must believe in the product. Anyways they ended up sending me a new kit and all was good.