Ham-
I don't know how much of a
rig you'd need to remove the boat...but maybe it is worth taking a shot. Right now, before the yard is stacked up with winter storage and your boat just "can't be reached".
Get out the title to your boat. Call a transporter, whatever you need, and go to the yard to pick it up. If the yard refuses to release it, you call the police--preferably the county or state police, not a local who might be in his pocket.
With the officer as a witness, you say "This is titled property, this is my property, I am taking my property. If you refuse to release it, I will ask the officer to arrest you for wrongful retention. If you have any claims against my property, you can file them in court."
It *IS* titled property, and whether the yard has claims or not, the police are required to help you recover your property from anyone who is "retaining" it.
If you go to the local state police barracks (who might say it isn't their jurisdcition) or sheriff (who might charge a fee) and schedule the trip ahead of time, they might accompany you and the hauler on the way in.
But if you wait another month--the yard will have the excuse "We can't reach it, there are too many boats in the way" and then you'll owe them winter storage.
Worth discussing with your attorney.