Re: [Amel Yacht Owners] Re: Tonnage

Beaute Olivier


What Bill K says is right.
On a British Registry Certificate for a Super Maramu, the Gross tonnage is 33.24, the Register tonnage is 23.35. I remember people from Bureau Veritas coming to the Amel Shipyard and measuring the boats that would fly a British flag.
Today, a vessel tonnage is only mentionned with a figure : The tonnage of this vessel is 480. There are rules for vessels of a tonnage above 500.
What is  a tonnage? A volume calculated differently according to the countries of registration. In France a Super Maramu's tonnage is 30.14.
The "tons" expressed previously is in fact 100 cubic feet. This is international for all kinds of vessels. Yes, even the French use this system (tons, which in French is named tonneau, which means "barrel"). 100 cubic feet is approximately 2.83 cubic meters.
This volume is mainly made and assessed to put several kinds of taxes on the vessel...cargo ships mainly but leisure crafts too.

Finally, if I say that the Super Maramu light displacement is 15.3 tons, this is a ton which weighs 1000 kg, the weight of one cubic meter of water. This is typically a metric figure.

And tonnage is not directly related to displacement. A Super Maramu made of carbon/foam sandwich would have a much lighter displacement but the same tonnage as your Super Maramus (in the same country of registration!!).

Since 2013, the tonnage of a leisure craft is no more mentioned in a French flag certificate...


On Wednesday, November 29, 2017 4:41 PM, "greatketch@... [amelyachtowners]" wrote:

Do not assume that the "tons" shown on your documentation certificate has anything to do with the vessel's weight.

It is an archaic calculation that is an estimate of the boat's cargo carrying capacity based on its volume. On US certificates it is calculated from the boat’s width, height, and length.  

Because, you know many of us haul freight with our Amel’s and the government needs to be sure it gets its duties collected accurately.  Or something.

Some countries use a rough approximate calculation (like the USA and the UK) others take this to the silly limit and require an exact calculation of the internal volume from a lines drawing of the hull.  The whole concept is rather a waste to time and energy  for a yacht, but rules is rules!

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL

---In amelyachtowners@..., wrote :

Follow on from my previous. That is way more than Amel specs.
Sm 299
Ocean Pearl
Sent from my Vodafone Smart
On 29 Nov 2017 18:29, "'sailormon' kimberlite@... [amelyachtowners]"
Kimberlites stated tonnage on the USA Documentation is 25 net tons and 28 gross  tons.
Fair Winds
Kimberlite Amel Super Maramu #376
 the gross/net  tonnage, so that the official measure can
make the International certificate of
tonnage.Have you recieved any info which can
help?Kind RegardsJeppe, SM464


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