I live in NY, and can tell you that Bird is correct in his assesment of what my Allstate Homeowners covered. Normal perils, but not the collision and upset which Kubota also required. I ended up getting an Inland Marine policy from Erie&Niagra that covers the unit and it's attachments for most everything but not at replacement cost. Also that policy does not cover liability on others property, so that is where my homeowners would kick in again. That policy cost me $75.00/yr.
I had a difficult time finding someone to insure. State Farm would, but the agent said only if I had other insurance with them. Several others wouldn't even insure. Erie & Niagra may require additional insurance, but I did not check as I already had another policy with them.