For the exterior you would be better to use one of the other products designed for what you need.
Steel Flex,Gator Glide, and Frog spit are the more common ones that I am aware of. they are a flexible but extremely durable coating. They are also very slippery! Some of them have teflon or other like substances in them. Airboaters use it to run over dry ground. Even though it flexes with the hull of the boat it also makes it stronger. Plus it will fill in gaps in rivets and small imperfections.
It is still a good idea to re-buck/replace any loose rivets and fix any leaks you have prior to putting it on.
You can get LineX sprayed in a smooth finish and that (I have heard) is great for the underside, or any where else on the boat.
Not sure how many LineX shops there are in PI though? I assumed you were talking about one of the do it yourself bedliners like Herculiner or something. I wouldnt use anything like that on the outside of a boat!