I have a 1977 Hunter 27 that I would like to document. Can anyone with a USCG documented Hunter 27 tell me what is the gross tonnage of their boat? What is the height applied by the Coast Guard in the Simplified Measurement formula?
Gross Tonnage for H27?
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The complete Simplified Measurement formula
Though I'm not sure why anyone would call it "simplified"... Take the horizontal distance over the centerline between the outboard ends of the boat not including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel. Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100. This will give you the "Gross Tonnage". Net tonnage is 90% of gross for sailboats and 80% for power boats.
Though I'm not sure why anyone would call it "simplified"... Take the horizontal distance over the centerline between the outboard ends of the boat not including rudders and bow sprits. Multiply that by the maximum beam outside to outside. Multiply that by the distance from the sheer line not including bulwarks or cap rails to the outside bottom of the hull not including the keel. Add the volume of the deck house/cabin top. Multiply by .5 for sailboats and .67 for power boats. Divide by 100. This will give you the "Gross Tonnage". Net tonnage is 90% of gross for sailboats and 80% for power boats.
My 386 Doc papers ....
... show 13 Gross and 12 net. As a relative guideline, this might be helpful to determine if your numbers are out of wack ( or, in wack). Peggys numbers came close on my boat. Jeff
... show 13 Gross and 12 net. As a relative guideline, this might be helpful to determine if your numbers are out of wack ( or, in wack). Peggys numbers came close on my boat. Jeff
Origin of ship's tonnage...
Tonnage has nothing to do with the weight of your boat or displacement. It was originally a measure of how much wine a vessel can carry. The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size. It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per ton. Another bit of maritime trivia: the origin of the term "rummage sale." Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. After a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale.
Tonnage has nothing to do with the weight of your boat or displacement. It was originally a measure of how much wine a vessel can carry. The word "tun" was originally a size of a cask used to ship wine from Spain & Portugal to England. In 1347 a tax of 3 shillings per tun was imposed and this was called "tonnage." A ship's size became known by the number of casks it could carry, and the word tonnage started being used to describe a ship's size. It was found that if you took the length x the breadth x the depth of the hold under the deck and divided by 100 it was close to the number of casks. That is where we get the "Measurement ton" of 100 cubic feet per ton. Another bit of maritime trivia: the origin of the term "rummage sale." Rummage was the manner in which the wine casks were stored in the hold of the ship and came to refer to the whole ship's cargo. After a voyage any unclaimed and damaged cargo was stacked on the dock beside the boat and offered for sale - a rummage sale.
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