Gross Tonnage/Net Tonnage?

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jimmy alonso
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Gross Tonnage/Net Tonnage?

Post by jimmy alonso »

Planning for a BVI trip soon and there's a new web site for vessel info.

What is the Gross Tonnage for a :macm: :?:
Also Net Tonnage?

Which is a better option Sloop or Mono Hull?



Thanks
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Sea Shadow
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Re: Gross Tonnage/Net Tonnage?

Post by Sea Shadow »

According to factory specs the empty weight of an M26 is 1157kg. Add motor weight, in my case an Evinrude 60hp Etec at 113kg. Orignal single axle trailer 241kg. The would make a nett weight of 1511kg. Gross weight would be adding all the stuff you put on the boat i.e. fuel, supplies, equipment etc. Suggest you would get the gross weight by loading the boat up with your gear that you are going to tow around and get onto a weighbridge.

I do believe a "Sloop" is a mono-hull. A "sloop" is a one masted sailboat with a mainsail and forefsail mounted aft and fore, i.e. the Macgregors are sloops.
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jimmy alonso
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Re: Gross Tonnage/Net Tonnage?

Post by jimmy alonso »

Thanks for the reply
I came up with Net and Gross of 4 using the calculator in the below link using Length 26 feet, Breadth 8 and Depth 4
Not close to my boat so I estimated Depth. This is also used to see if you can get US Coast Guard Documentation for your boat which requires a minimum of 5 Gross tonnes.

I found this info here https://www.delawarebusinessincorporato ... calculator

How to calculate gross tonnage of recreational vessels?

The internal volume of a water-going vessel has what is called gross tonnage.

Volume is measured from keel to funnel and from bow to stern. Crew spaces and other parts of the vessel that do not hold cargo are deducted from the measurement.

Since most vessels have an asymmetrical shape it can be difficult to determine the actual gross tonnage.

A simplified set of small boat gross tonnage formulas is set forth by the U.S. Coast Guard, which are based on three measurements: Length (L), breadth (D), and depth (D). Under this system, the means of estimating gross tonnage is as follows:

For a boat with a simple sailing hull: Gross Tonnage = (.5 x L x B x D) divided by 100.


Also this PDF show how to measure your boat https://cdn.shopify.com/s/files/1/1021/ ... t.pdf?1513
Duquette5
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Re: Gross Tonnage/Net Tonnage?

Post by Duquette5 »

Wouldnt depth be measured as depth of area? Without running outside with a tape if you divided the hull length into 3 separate sections: aftberth (7'), forward berth(7') and mid (12'). The respective (guesstimate) depths would be 3.5', 5', and 6'. Averaged that is 4.833 that gives you 5.02. Consider also that the ballast tank is not calculated into this but should be. The argument could be made that you meet the tonnage requirement.
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Stickinthemud57
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Re: Gross Tonnage/Net Tonnage?

Post by Stickinthemud57 »

I think Sea Shadow has it nailed. Go with the factory weight and estimate the rest, or find a scale.
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Wyb2
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Re: Gross Tonnage/Net Tonnage?

Post by Wyb2 »

The PDF and the calculator are right. Ship tonnage is a poorly named and inaccurate measure of the volume of a ship/boat. It has nothing to do with weight.

https://en.m.wikipedia.org/wiki/Gross_tonnage

4 seems about right for a small sailboat. Looks like if you plug in a ‘depth’ of 5 you can hit the CG min for documentation if you wanted to. I don’t think anyone comes out and measures your boat.

For the BVI form, I highly doubt they care that much about accuracy, just trying to get a general idea of size. For type I’d put sloop, just to indicate that it’s a sailboat vs a monohull powerboat.
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