If you talking about a small utility boat like a Lund, i.e. fishing boat, I'd guess no more that 1200 pounds and I think I'm high...really need more info on boat.
Heinz,<br /><br />Nothing better than a "real" weight. Go to a moving and storage warehouse, they always have scales and will weigh it for you for about $10.00.
why not just stop at a truck weight station when it is closed? 99% of the time the scales will still be on..... and you can get to the nearest 50 pounds that way....
