There are issues withe registering it and not registering it.

Registering it will be difficult because you have a 15 ft factory boat with serial numbers and a transfer document that lists it as a 14 home built with no serial numbers (removing or changing the serial numbers is a crime (probably) at a couple of levels). If you want to register the boat call whoever registers boats in your state, tell them what you have, ask them what you have to do, get the name of the person you are talking to, do exactly what they tell you (even if it sounds crazy), take everything to whoever you are told to take it to and tell whoever helps you that "so and so" said this is what I had to do. This works in most States, Florida may be an exception.

Not registering it has problems too. You have a 15 ft factory boat with serial numbers and a transfer document that lists it as a 14 home built with no serial numbers. If you get caught by a registration check, the best case is you will just pay a fine. The worst case I can think of is that they will run a check on the serial probably years later, because it is LOW priority, find it was reported stolen in another state, you have a suspicious transfer document and now you have a mess. This is farfetched because most sail only boats, more than 20 years old were never registered.

Anyway, good luck. I wish states were honest with us. They don't give a crap about us and they are not going to investigate if we report the boat stolen. They just want our money. There should be an easier way where we just send money and they don't pretend.