Re: insurance
You can never get replacement value on vehicles. You can get an agreed value policy that will insure it for an amount greater than book value, but the boat should at least be worth what you insure it for. Examples - a mint condition garage stored classic that is like new, or a restored woodie that is now worth 10 times what it cost new.
If you have a old junker and you're trying to insure it to buy a new one if damage occurs, forget it. What you DO need, though, is liability insurance, to protect the other guy should you have an accident, and protect you from a lawsuit.