Nonsuch 26U net tonnage

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John Phillips

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Jun 7, 2022, 11:24:13 AM6/7/22
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Forgive me if the answer is already in the discussion group, but a search on several key words did not reveal it to me.

The question is will a Nonsuch 26U pass the minimum 5 Net Ton requirement for federal boat documentation?  If you have any tips about the simplified measurement (CG-5397 form) application for federal documentation, please advise.

Thank you in advance.

John Phillips

Jim Cosgrove

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Jun 7, 2022, 11:40:05 AM6/7/22
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John,

My 1984 26C was USCG documented. It was documented when I purchased it so unfortunately I don’t have measuring tips. 

Jim Cosgrove 
FATE 30U #343
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Bob Neches (Me Gusta, Nonsuch 26U #233)

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Jun 7, 2022, 1:29:07 PM6/7/22
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John,

You can calculate it using the formula on pages 7-8 of the attached USCG document.  The numbers you need are all on the "Principal Dimensions" page of the N26U manual, which is the fourth page in my copy.

With one exception: for "Overall Depth" (D) the number needed is the draft (4' 6") + the height from the deck to the water.  The latter I think is easiest found by measuring your boat since I'm not aware of any document giving it.

I'm curious, but short on time just now, so I'll work through it myself and come back later with my calculations.

-- Bob
   Me Gusta
   Nonsuch 26U #233
Tonnage Guide 1 - Simplified Measurement.pdf

John Phillips

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Jun 7, 2022, 2:07:18 PM6/7/22
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Thank you very much.

One additional question.  Were all Nonsuch 26's built in Canada?  My boat has a decal that says, "Hinterhoeller Yacht Corporation, Newport, RI".

John Barbour - Nature 26U Toronto

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Jun 7, 2022, 10:06:23 PM6/7/22
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My 26U is federally registered with Transport Canada
From the Certificate of Registry:
The gross tonnage is  7.56  and the Net/register tonnage is  is 7.07
Length 7.41m, Breadth 3.26 m, and Depth 1.31 m
Builder: Hinterhoeller Yachts Ltd, St. Catharines, ON 
Vessel description: pleasure craft
Build: 1987

John Barbour
Nature 26 U Toronto

John Phillips

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Jun 7, 2022, 10:47:46 PM6/7/22
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Thank you.  That is very helpful.  The Depth variable was the one I was most concerned with.

Sent from my iPhone

On Jun 7, 2022, at 10:06 PM, John Barbour - Nature 26U Toronto <jhba...@gmail.com> wrote:

My 26U is federally registered with Transport Canada

Bob Neches (Me Gusta, Nonsuch 26U #233)

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Jun 7, 2022, 11:47:23 PM6/7/22
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John,

What's the hull number and Hull Identification Number on your boat?   And where is this decal?  Very unlikely that it was built anywhere other than St. Catherines, Ontario, Canada.

As for the calculation of Gross Tonnage for U.S. federal documented vessels, here's what I could figure out from looking at the rules more closely when I got back this evening from sailing.

First, the rules say, "Deck structure volume is accounted for only if the volume of the principal deck structure is equal to or greater than the hull volume."

 Not true for a Nonsuch, so the only numbers needed are: GRT = Hull Volume / 100 = (S x K x L x B x D) / 100, where:
  • S = 0.5 for hulls designed for sailing (finest hull form)
  • K = 1 for sailboats shaped like ours (i.e., fin keel and a rounded hull cross-section)
  • L = Overall Length = 26'
  • B = Overall Breadth (Max Beam) = 10.5'
  • D = Overall Depth (which for our type of boat is considered to be the draft of the hull, keel not included).   I believe that to be 5 ft.  Explanation of why follows in case someone wants to check my reasoning.
For our boats, D is the only one that's a bit tricky.
USCG D definition for Gross Tonnage.jpgI wrote too quickly this morning when I said D was the height above the waterline -- this is NOT the height above the waterline.  It would be the height above the waterline (which I measured this afternoon at 34 inches), plus the distance from there to the exterior bottom of the hull.  I don't know that latter number, but I happen to know from work I did and a discussion with the designer that the floor is 15 inches below the waterline.   Now I happen to have a cross-section drawing of an N26U.  (See attached picture.)  Measuring the distance in that drawing from the  floor to the hull bottom, I get that remaining distance as about 3/4ths of distance in the drawing from floor to waterline.  Three-quarters of 15" is 11.5 inches.  That makes D = 34" (exterior deck to waterline) + 15" (waterline to floor) + 11.5" (floor to hull bottom) = 60.5 inches = about 5 ft.

Assuming my numbers are right, that gives you Hull Volume = 0.5 (S) x 1 (K) x 26' (L) x 10.5 ' (B) x 5 (D) = 682.5

Since GRT is that divided by 100 that works out to, GRT = 6.825  for the purposes of US Coast Guard Federally Documented Vessels.

I hope I'm not the only one chipping in, and that others either have the information or at least can check my match.

But that's my current best guess.

-- Bob
   Me Gusta
   Nonsuch 26U #233


Ns26U sectn.jpg
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