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Debunking Dodgy Sailing Theories

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JohnW View Drop Down
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Post Options Post Options   Quote JohnW Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 11:32am
Originally posted by fudheid

Originally posted by JohnW

How about this old chestnut:

"the fastest way to round the leeward mark is 'wide in tight out' "


not the fastest but the best way, inside track upwind.....

No, not always the "best" way.

Agree wide in tight out has tactical advantages, but in the absence of other nearby boats an apex turn is faster by around a boat length (which in my book is generally better when racing). 

The myth is that being further "upwind" is better, in reality the apex turn puts you ahead of where you would have been if you had done the  "racing turn".  You may be slightly to leeward of the exit line from the mark, but because you sailed a shorter distance you are in fact ahead by about a boat length.


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Post Options Post Options   Quote Isis Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 11:36am
Originally posted by I luv Wight

What is planing? and how do you define it?


When a significant proportion of the displacement is supported by dynamic lift.

What qualifies as significant? thats the tricky bit.
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Post Options Post Options   Quote Beast of Bodmin Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 11:38am
Was recently told that with only 5 knots at sea level you can regularly see 30 knots at mast tip ( 30ft for us ) .Came from a very reliable source but doesn't seem possible or apparent to me . What's your expereince ?
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Post Options Post Options   Quote rogue Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 11:47am
Originally posted by I luv Wight

What is planing? and how do you define it?


it's the thing that means the same thing as planning on a sailing forum, however it is spelt correctly.
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 12:12pm
Originally posted by Beast of Bodmin

Was recently told that with only 5 knots at sea level you can regularly see 30 knots at mast tip ( 30ft for us ) .Came from a very reliable source but doesn't seem possible or apparent to me . What's your expereince ?


Depends what you mean by 'sea level'. 10cm? 1m?
If you measure at three metres and ten metres, there is usually a measurable difference, 20% is sometimes used as a rule of thumb, but it varies I believe.
The true wind direction also varies!
Air close to the ground spirals into the low pressure more steeply than faster moving air high up.

But in reality, these big picture simplifications are often obscured by local effects.
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Post Options Post Options   Quote fudheid Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 1:50pm
Originally posted by JohnW

Originally posted by fudheid

Originally posted by JohnW

How about this old chestnut:

"the fastest way to round the leeward mark is 'wide in tight out' "


not the fastest but the best way, inside track upwind.....

No, not always the "best" way.

Agree wide in tight out has tactical advantages, but in the absence of other nearby boats an apex turn is faster by around a boat length (which in my book is generally better when racing). 

The myth is that being further "upwind" is better, in reality the apex turn puts you ahead of where you would have been if you had done the  "racing turn".  You may be slightly to leeward of the exit line from the mark, but because you sailed a shorter distance you are in fact ahead by about a boat length.



Don't you just do the apex turn so you come out next to the mark??
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JohnW View Drop Down
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Post Options Post Options   Quote JohnW Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 2:31pm
Originally posted by fudheid

Don't you just do the apex turn so you come out next to the mark??

If you come out next to the mark it is not an Apex turn.  I was going to draw a diagram, but this article explains it better than I could:



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Post Options Post Options   Quote I luv Wight Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 10:29pm
Originally posted by I luv Wight

What is planing? 

This is definitely planing, ( ie exceeding the hull speed of a foot = 1.43 knots according to some theories)
http://youtu.be/IlruXNU9i6k

http://www.bloodaxeboats.co.uk
Andy P
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Peaky View Drop Down
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Post Options Post Options   Quote Peaky Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 10:48pm
No no no no no. Planing has nothing to do with exceeding a particular speed.
I can't see the video at the moment, hope it's a good one!

Edited by Peaky - 21 Oct 11 at 10:51pm
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I luv Wight View Drop Down
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Post Options Post Options   Quote I luv Wight Quote  Post ReplyReply Direct Link To This Post Posted: 21 Oct 11 at 11:04pm
Originally posted by Peaky

No no no no no. Planing has nothing to do with exceeding a particular speed.
I can't see the video at the moment, hope it's a good one!



Err... see the title of the thread!



http://www.bloodaxeboats.co.uk
Andy P
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