Sail Dimension Help - SailNet Community

   Search Sailnet:

 forums  store  

Quick Menu
Boat Reviews  
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Hatches and Portlights
Interior And Galley
Marine Electronics
Other Items
Plumbing and Pumps
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here

Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 
Old 06-23-2009
DrB DrB is offline
Senior Member
Join Date: Mar 2007
Location: New England
Posts: 966
Thanks: 0
Thanked 7 Times in 7 Posts
Rep Power: 9
DrB will become famous soon enough
Sail Dimension Help

Looking to get a new headsail for my boat. I would like to get a new "used" one that is in excellent condition, maybe a lightly used race sail, to save money over a true new one.

The issue that I ma having is trying to figure out if the dimension of the headsail from the dimensions of the rig.

The P dimension of my boat is 40.5, the I=46.0, J = 14.2, and E=11.0. So to get the max. luff dimension, along the headstay, with out measuring my current sail, I calculated Max Luff equals Square root of (I^2 + J^2) = 48.14 ft. That assumes that I tack the sail right to the deck. I am guessing that the RF tack fitting is about 12 inches off the deck, so now the Max Luff is around 47.14.

If I wanted a sail that was between 130 and 140% of the foretriangle, I am guessing that the headsail foot dimension is between 18.46 and 20.

So when looking for a sail The Luff measurement should be no more than 47.1, but best if between 47 to 46 ft, the leech no more than 46, and the foot (J) between 18.5 and 20 ft.

Are my calculations correct?


If you liked my advice/response, give me some rep points. If you didn't......well what do you expect, it was free.
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
Join Date: Jul 2006
Posts: 73
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 9
Gary3675 is on a distinguished road
Go to Bacon sails
Bacon Sails & Marine Supplies

Towards the bottom of that page you can search for by boat

"Search our inventory by your boats factory specifications!!"

This will give you dimension if your boat is in their data base
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
Jeff_H's Avatar
Join Date: Feb 2000
Location: Annapolis, Md
Posts: 6,809
Thanks: 5
Thanked 130 Times in 104 Posts
Rep Power: 10
Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about Jeff_H has a spectacular aura about
More likely than not your dimensions bear little resemblance to what you will actually need. The calculation is not all that likely to produce an accurate forestay length off of the PHRF measurements. Boats vary quite widely from their class measurements.

But beyond that the difference between the forestay length and the luff length needs to include room for the stay connection/ swage, halyard box, some room for stretch, and clearance for the roller furler head swivel fitting.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Curmudgeon at Large- and rhinestone in the rough, sailing my Farr 11.6 on the Chesapeake Bay
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
Faster's Avatar
Just another Moderator
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 16,304
Thanks: 100
Thanked 301 Times in 291 Posts
Rep Power: 10
Faster has a spectacular aura about Faster has a spectacular aura about Faster has a spectacular aura about
Most sailmakers will measure your boat before building the sail - this assures the proper fit/set. Jib lead track/car locations, spreader angles/height, etc etc all combine to affect just how your sail should be built.

Having your sailmaker check out YOUR boat will result in a better sail. This is what makes me nervous about buying a sail from FX or other on-line lofts...

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
zz4gta's Avatar
I don't discuss my member
Join Date: Aug 2007
Location: Chesapeake Bay
Posts: 2,525
Thanks: 0
Thanked 31 Times in 31 Posts
Rep Power: 8
zz4gta is on a distinguished road
I agree, I ran into major problems trying to get online dimensions for a new headsail. You can measure for a new sail yourself, shoot me a PM and I'll forward you an email with what the sailmaker requires.
Merit 25 # 764 "Audrey"
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
okawbow's Avatar
Senior Member
Join Date: Feb 2007
Location: Illinois
Posts: 237
Thanks: 2
Thanked 4 Times in 4 Posts
Rep Power: 9
okawbow is on a distinguished road
I draw a scale line drawing of my boat, (or use one I find online.) You need to know the mast height, and distance from the mast to the head stay plate. The head stay length is also needed. The luff, leech and foot measurements of the used sail, can be compared to the scale drawing to see if it will fit. The used sail is converted to the same scale as the drawing. I've bought a couple of head sails using this method, that fit well. Draw in the position of your genoa tracks to be sure the lead angles will work.

Privateer 26 Schooner
Reply With Quote Quick reply to this message Share with Facebook
Old 06-23-2009
JimsCAL's Avatar
Senior Member
Join Date: May 2007
Location: Glen Cove, NY
Posts: 2,666
Thanks: 2
Thanked 60 Times in 55 Posts
Rep Power: 9
JimsCAL is on a distinguished road
Finding a used headsail that will fit a furler is not going to be easy. If the sail luff is too long or too short you are going to have problems with the furler. With hanks you can use a sail that's not full hoist, but not on a furler. Both FX and North Sails Direct will give you quick quotes based on your boat model, but you will need to make a number of measurements before an order can be placed. I ordered a main from North when they were called Cruising Direct 7 years ago and it fit perfectly and is holding up well.

Last edited by JimsCAL; 06-23-2009 at 05:41 PM.
Reply With Quote Quick reply to this message Share with Facebook

Quick Reply

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now

In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Heavy weather sailing sailorfrank Learning to Sail 26 09-10-2013 06:32 PM
Sloop, Cutter or Ketch jsgsail Boat Review and Purchase Forum 17 12-26-2008 02:47 PM
What is the point of a traveller? dwbecker Learning to Sail 9 09-25-2006 08:35 PM
Sail Care and Cleaning Kathy Barron Gear and Maintenance Articles 0 10-20-2003 08:00 PM
First Sail of the Season Bruce Caldwell Seamanship Articles 0 06-05-2003 08:00 PM

All times are GMT -4. The time now is 06:39 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) LLC 2000-2012

The store is owned and operated by a company independent of the forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.