Leeway

[flaming]

Re: Consider the keel as a sail as well ...

[ QUOTE ]

[/ QUOTE ]

I seem to remember that this was tried on the old 12 metres that used to be used for the America's cup but discarded because they were slower.

 

[Litotes]

Re: Leeway: Here\'s the only answer

[ QUOTE ]
And there was me thinking that Leeway was the accumulative effects that changed the boats COG from direction that you were pointing it to!


[/ QUOTE ]

Except that, by this definition, your leeway could rather easily end up being weatherway.

 

[LadyInBed]

Re: Leeway: Here\'s the only answer

No, definitely not.
I have Weatherway - Defined as "is the weather suitable for setting off or not".

 

[GruffT]

Re: Leeway: Here\'s the only answer

Surely Leeway is simply a name given to a witnessed effect of forces acting on a boat when the wind blows i.e. shoving it sideways. I’d argue that exactly what makes up the combination of stuff (wind, sail plan, keel, heel, sea state, what we had for lunch, which anchor we're carrying etc etc etc) isn't really important - it's the evidence of it that's the thing and how if effects my system, i.e. the boat crabbing slightly and the impact that has on navigation.

IIRC Feynman said something similar. Oh and Heisenberg, and Schrödinger - although his argument was more cat based.

Of course if I was designing a boat I may want to minimise the effect but I could approach that in a number of ways - and that's a whole new thread.

Point in brief : it's just an agreed name for a witnessed effect. Nothing more.

 

[Litotes]

Re: Leeway: Here\'s the only answer

Hmmmm.....So, when you sail across a strong weather going tide, reaching with a light wind, and end up to windward of the buoy for which you set your course, that's still leeway?

 

[boguing]

Re: Consider the keel as a sail as well ...

[ QUOTE ]
I seem to remember that this was tried on the old 12 metres that used to be used for the America's cup but discarded because they were slower.

[/ QUOTE ]

That wasn't used on 12 Meters. It's a Warwick Collins designed 'Tandem Keel'. Got fitted to various production boats, and most notably his rather nice 'Fighter'.

He famously told Malcolm McKeag of Yachts & Yachting "the clever bit is that any cross tide goes through the wee hole in the middle".

 

[Cerddinen]

Re: Leeway: Here\'s the only answer

Now we don't even know what it is, never mind how to explain it ...

Godel would be delighted by the progress of this thread.

 

[Litotes]

Re: Leeway: Here\'s the only answer

Oh, but I think we do. I'm just interested in the boundaries of LadyInBed's definition, which is acknowledged to be incorrect.

 

[sailorman]

Re: Leeway: Here\'s the only answer

http://www.sailtrain.co.uk/navigation/cts.htm


Leeway with a course to steer
If there is leeway when you are working out the course to steer there is no change in the calculations. Everything is worked out as if there was no leeway, but the last step once you have the water track is to decide if the leeway is to be added or subtracted from the water track to find the correct course to steer. This is the course that is passed to the helmsman.

Leeway is applied in to the wind with a course to steer as you are countering the effect it is going to have.

 

[jimi]

Re: Leeway: Here\'s the only answer

Jings!!!!!!!!!!!!!!!!!!!!

Leeway is the drift through the water of a vessel to leeward of the course being steered. This is caused by either the wind or waves or a a combination of both. Tidal set is something completely different and I'm gonna sink the nut in any moron who dares to disagree

 

[sailorman]

Re: Leeway: Here\'s the only answer

You are Correct Sir. some dont seem or want 2 understand the principle

 

[Litotes]

Re: Leeway: Here\'s the only answer

Thank you for the lesson - one I learned approximately 45 years ago! /forums/images/graemlins/smile.gif

I think you have misunderstood my post, as has Jazz.

 

[john_morris_uk]

Re: Leeway: Here\'s the only answer

[ QUOTE ]
Hmmmm.....So, when you sail across a strong weather going tide, reaching with a light wind, and end up to windward of the buoy for which you set your course, that's still leeway?

[/ QUOTE ]Yes, the boat has still made some leeway. Its just that the effects of the tide have counteracted the leeway and you have gained to windward with the tide pushing you 'upwind'.

Leeway is what happens 'through the water'. Is some of the misunderstanding over the whole business of leeway due to navigation nowadays mainly being done by plotters and GPS which always shows your course and track etc over the ground? When we had to plot course through the water, and then plot EP's from tidal data, a sense of what was happening to the boat with leeway might have been a bit clearer?

 

[sailorman]

Re: Leeway: Here\'s the only answer

R U JTR then /forums/images/graemlins/confused.gif
he asked first

 

[colingr]

Re: Leeway: Here\'s the only answer

I'm standing with / behind Jimi (safest place to be) /forums/images/graemlins/shocked.gif

 

[oldsalt]

Re: Leeway: Here\'s the only answer

Looks like you will be giving me a Glasgow Kiss...

Leeway has nothing to do with waves...

Apart from sailing dead downwind, the keel acts as a foil. It prevents most"sideways" movement, but allows "forward" movement. It is like a wing in that it has an angle of attack, drag etc etc.

Assuming you don't have a complete plonker as a skipper who sheets in the sails hard on a beam reach, an efficient keel allows little leeway and an inefficient keel a lot of leeway. No way is the leeway zero.

As a previous poster correctly noted, just sail a dinghy close hauled, and pull up the centre-board. This will teach you more about leeway than any RYA shore based class...

 

[sailorman]

Re: Leeway: Here\'s the only answer

Leeway is most apparent going to windward makes little difference on any other point of sail

http://www.sailtrain.co.uk/navigation/cts.htm

 

[Litotes]

Re: Leeway: Here\'s the only answer

You, too, have misunderstood my post. I am not asking LadyInBed for clarification of the meaning of leeway, but for clarification of what he, or she, thinks is leeway. There is a rather large difference.

To save anyone else the trouble of patiently explaining this term to me:

I know what leeway is
I know how to apply it in navigation and pilotage
I know it still applies in the example I have given
I have known these things for around 45 years
I have taught a goodly number of people to apply these calculations in their chartwork
I apply them in my own chartwork
I am interested in the interpretation put forward by LadyInBed, which is acknowledged to be incorrect. Does LadyInBed still think of it as leeway, even when the accumulation of forces he or she mentions move the boat in a windward direction in relation to the course to steer, which is to say that the effects of leeway, which are, of course, still present, are weaker than the effects of tidal set.

Does that clarify matters? /forums/images/graemlins/smile.gif

 

[sailorman]

Re: Leeway: Here\'s the only answer

Sorry missed wot you were getting @. /forums/images/graemlins/blush.gif
it seem the Lady isnt quite sure /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif

 

[jimi]

Re: Leeway: Here\'s the only answer

[ QUOTE ]
Looks like you will be giving me a Glasgow Kiss...

Leeway has nothing to do with waves...


[/ QUOTE ]


Absolute bollox, look at the angle of your wake to your heading when beating in a rough sea and then compare that angle with the same wind strength in flat water!!!!!!!