Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 03-08-2015, 16:05   #16
Registered User
 
Wrong's Avatar

Join Date: Jul 2013
Posts: 1,702
Re: Seamanship

My view is diametrically opposed to the idea striking the main is a best case scenario in most situations. The one exception is on approach to one's destination. In this case, provided the wind is not too close to maintain course and speed under jib alone, lowering the main en route is a good choice.

However, I often wonder what sailors will do in the case conditions require heaving to and the main is down... A mainsail with three reefs provides the option of reefing down and sailing under main alone on most tacks without putting excess strain on the mast and rigging. Faced with the need one can still heave to. Not so with only a headsail up...
__________________

__________________
Wrong is offline   Reply With Quote
Old 04-08-2015, 04:33   #17
Registered User
 
Rustic Charm's Avatar

Join Date: Jun 2011
Location: Tasmania, Australia
Boat: Bieroc 36 foot Ketch
Posts: 4,898
Re: Seamanship

Quote:
Originally Posted by StuM View Post
Specifically, it's LP (Luff Perpendicular) which is the width from luff to clew at right angles to the luff. (as opposed to at the foot which some people think.

Once again Wikipedia gets it wrong. Note that a 100% genoa overlaps the mast, contrary to what Wikipedia's definition would imply.
Doh! now I'm all confused. If wiki is wrong (which flabbergasts me), can someone sketch a rough idea of what your talking about?
__________________

__________________
Rustic Charm is offline   Reply With Quote
Old 04-08-2015, 04:50   #18
Registered User

Join Date: Mar 2015
Posts: 13
Re: Seamanship

Would the same principles hold true for a catamaran
__________________
sjaversa is offline   Reply With Quote
Old 04-08-2015, 05:22   #19
Senior Cruiser
 
StuM's Avatar

Cruisers Forum Supporter

Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43
Posts: 6,713
Re: Seamanship

Quote:
Originally Posted by sjaversa View Post
Would the same principles hold true for a catamaran
Yes, that is correct. (The forum software wouldn't let me just post the word 'Yes" by itself)
__________________
StuM is online now   Reply With Quote
Old 04-08-2015, 05:55   #20
Senior Cruiser
 
StuM's Avatar

Cruisers Forum Supporter

Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43
Posts: 6,713
Re: Seamanship

Quote:
Originally Posted by Rustic Charm View Post
Doh! now I'm all confused. If wiki is wrong (which flabbergasts me), can someone sketch a rough idea of what your talking about?
Wikipedia says "Genoas are categorized by a percentage representing their area relative to the 100% foretriangle"

It is actually LP/J expressed as a percentage.

in the drawing below, the sail (green) triangle is 100% of the foretriangle, but the LP measurement is considerably less than the J measurement, so this is not a Genoa, it is something around a 90% jib.





A 100% sail where LP = J would, of necessity, extend back past the mast.

__________________
StuM is online now   Reply With Quote
Old 04-08-2015, 06:03   #21
Registered User
 
OldFrog75's Avatar

Join Date: Feb 2013
Location: Santa Monica, CA
Boat: Club Sailor; various
Posts: 922
Re: Seamanship

Quote:
Originally Posted by StuM View Post
Wikipedia says "Genoas are categorized by a percentage representing their area relative to the 100% foretriangle"

It is actually LP/J expressed as a percentage.

in the drawing below, the sail (green) triangle is 100% of the foretriangle, but the LP measurement is considerably less than the J measurement, so this is not a Genoa, it is something around a 90% jib. A 100% sail where LP = J would, of necessity, extend back past the mast.



I said the same thing in an earlier post (posited more as a rhetorical question) further up but I should have known Stu would get on the case in his usual inimitable and thorough style.

A picture is truly worth a thousand words.



PS. But I still don't understand why the industry uses this convention rather than simply dividing Foot/J. Would be a lot less confusing.
__________________
OldFrog75 is offline   Reply With Quote
Old 04-08-2015, 06:19   #22
Senior Cruiser
 
StuM's Avatar

Cruisers Forum Supporter

Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43
Posts: 6,713
Re: Seamanship

Quote:
Originally Posted by OldFrog75 View Post
Wouldn't it be easier to just divide the length of the foot by the "J" measurement and call it a day?
No, because the length of the foot doesn't determine the total sail area, but the LP does. A high cut yankee style sail and a deck sweeper with the same LP will have the same area, but will have very different foot lengths.

Think about it. The area of a triangle is 1/2 base x height which is 1/2 luff x LP). You can't work out the area of a triangle from the lengths of two adjacent sides. (luff and foot)
__________________
StuM is online now   Reply With Quote
Old 04-08-2015, 06:48   #23
Registered User
 
OldFrog75's Avatar

Join Date: Feb 2013
Location: Santa Monica, CA
Boat: Club Sailor; various
Posts: 922
Re: Seamanship

Ok. Now that the original thread has been thoroughly hijacked...

I thought the definition of a jib was 100% or less but the definition of a genoa was any overlapping headsail.

Since we've determined that a 100% sail is in fact overlapping does that mean the definition of a jib is 90% or less?

__________________
OldFrog75 is offline   Reply With Quote
Old 04-08-2015, 06:49   #24
Senior Cruiser
 
John_Trusty's Avatar

Cruisers Forum Supporter

Join Date: Oct 2014
Location: Michigan, USA
Boat: Catalina 36 (1999)
Posts: 235
Re: Seamanship

If Wikipedia is wrong, why not change it? We apparently have some real experts on this post, so why not one of you going to WP, delete the wrong and copy in the right. I guarantee that the average page hits on a WP link is much higher than the venerable Cruiser's Forum.

Not knocking my community, just saying that we need to spread the knowledge.
__________________
John_Trusty is offline   Reply With Quote
Old 04-08-2015, 06:58   #25
Registered User

Join Date: May 2013
Location: Mangareva, French Polynesia
Boat: Heritage West Indies 36
Posts: 513
Re: Seamanship

Quote:
Originally Posted by zeehag View Post
when picking a mooring, i double dog dare you to be able to steer a sailboat into th e position you need without the jib, so last sail down is jib.(engineless mooring pick up)
Hey Zee. I haven't yet found a boat where you couldn't sail up to a mooring under main alone, you just need a bit more room for reaching back and forth with the heavier, full-keeled variety. I approach on a reach, furl the genoa/jib and then the foredeck is free for dealing with the pickup. Then come up into the wind and stop the boat right by the mooring. The main doesn't come down until the boat is firmly on the mooring. That way, if i screw up there's still something up to bail out with!
__________________
DefinitelyMe is offline   Reply With Quote
Old 04-08-2015, 07:01   #26
Registered User

Join Date: May 2013
Location: Mangareva, French Polynesia
Boat: Heritage West Indies 36
Posts: 513
Re: Seamanship

Quote:
Originally Posted by Wrong View Post
My view is diametrically opposed to the idea striking the main is a best case scenario in most situations. The one exception is on approach to one's destination. In this case, provided the wind is not too close to maintain course and speed under jib alone, lowering the main en route is a good choice.

However, I often wonder what sailors will do in the case conditions require heaving to and the main is down... A mainsail with three reefs provides the option of reefing down and sailing under main alone on most tacks without putting excess strain on the mast and rigging. Faced with the need one can still heave to. Not so with only a headsail up...
A lot of boats will heave-to very nicely under storm jib alone, with no main. Some require it in fact. I've never come across two different boats that heave-to in the same way yet.
__________________
DefinitelyMe is offline   Reply With Quote
Old 04-08-2015, 07:05   #27
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,750
Re: Seamanship

Quote:
Originally Posted by StuM View Post
Wikipedia says "Genoas are categorized by a percentage representing their area relative to the 100% foretriangle"

It is actually LP/J expressed as a percentage.

in the drawing below, the sail (green) triangle is 100% of the foretriangle, but the LP measurement is considerably less than the J measurement, so this is not a Genoa, it is something around a 90% jib.





A 100% sail where LP = J would, of necessity, extend back past the mast.

Learn something every day!

Thanks, Stu!
__________________
Dockhead is offline   Reply With Quote
Old 04-08-2015, 07:14   #28
Eternal Member

Join Date: Apr 2014
Posts: 848
Re: Seamanship

Quote:
Originally Posted by DefinitelyMe View Post
A lot of boats will heave-to very nicely under storm jib alone, with no main. Some require it in fact. I've never come across two different boats that heave-to in the same way yet.
OK, I'm curious...

Can you name a few?

Fore-reaching I can see, but actually maintaining a classic hove-to position under a headsail alone? That I'd like to see...

;-)
__________________
Jon Eisberg is offline   Reply With Quote
Old 04-08-2015, 07:43   #29
Registered User

Join Date: May 2013
Location: Mangareva, French Polynesia
Boat: Heritage West Indies 36
Posts: 513
Re: Seamanship

Quote:
Originally Posted by Jon Eisberg View Post
OK, I'm curious...

Can you name a few?

Fore-reaching I can see, but actually maintaining a classic hove-to position under a headsail alone? That I'd like to see...

;-)
Well, mine's not too bad under jib alone but you're right, i guess it would be fore-reaching rather than heaving-to. I've also done it on a Beneteau 375, and the two are very different boats. I'm guessing you consider the 'classic hove-to position' to be going sideways and maybe a little forwards with the bow just a little off the wind? In that case no, i don't think i've ever tried that with just a jib and i don't think it would work very well as you need the strapped main to push the stern around and keep the bow into the wind. A couple of friends of mine reported having been hove-to (fore-reaching i guess you would say) in their maxi 95 off Bermuda (en route from the Bahamas) under jib alone. They liked having the beam on to the waves a bit more than the 'classic' posture would allow as it allowed them to slide down the face of the rather large swells they were encountering. It also allowed them to make way in the right direction without having to have anyone on deck.

I guess i've never really made the distinction between fore-reaching and being hove to. I started off on square-rig tallships and the term 'fore-reaching' wasn't a term we used.
__________________
DefinitelyMe is offline   Reply With Quote
Old 04-08-2015, 09:00   #30
Registered User

Join Date: Aug 2009
Location: New Jersey USA
Boat: Cape Dory 28 Sloop - s/v Kerry Deare of Barnegat
Posts: 197
Re: Seamanship

Quote:
Originally Posted by OldFrog75 View Post
... Wouldn't it be easier to just divide the length of the foot by the "J" measurement and call it a day? ...
Not to risk semantics, but if all jibs were cut as right triangles, then maybe so.

High clew jibs (sometimes called "reachers") don't qualify and would not give the same arithmetic result. Also many heavy weather jibs are cut "high" to avoid catching a big sea.

Even today I still think the Wall Ross book "Sail Power" says it all very well.
__________________

__________________
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http:\\yachtkerrydeare.blogspot.com
kerrydeare is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Why Sponsor and encourage Bad Seamanship? Pelagic Off Topic Forum 22 16-03-2017 18:26
'Seamanship' Pelagic Seamanship & Boat Handling 70 28-10-2009 07:03
Award for Outstanding Seamanship TaoJones Seamanship & Boat Handling 7 16-01-2009 09:40
Seamanship and Safety Kai Nui Challenges 0 09-08-2008 17:04
A most impressive demonstration of seamanship Craig Harlamoff Seamanship & Boat Handling 11 11-06-2006 00:45



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 19:04.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.