>>1617555The hard part isn't spraying the paint on, it's getting 300' of boat out of the water and dry so you can spray it on.
If it's literally just sitting still in a freshwater river on property you own, your day to day outgoings won't be huge but be aware that getting the boat to dry dock, using the dry dock and getting it back again every year or so will likely cost more than the total value of the boat in diesel alone.