Lee bow effect when running?
- Thread starter NDG
- Start date
flaming
Well-Known Member
Well a stable wind might oscilate between 5 and 10 degrees on about a 5 minute period. If that wind is 10 knots, and the tide in the channel is 3 knots, then I think you'll appreciate that the entirely predictable shift in a 6 hour period could be around 20 degrees. If you think this is not worth considering then I here by challenge you to a race to Cherbourg in a southerly!
Especially considering I've never met a cruiser yet who can spot a 5 degree shift, let alone one who tacks every five minutes to take advantage.
And as to this not being "the Lee bow effect". Well, no it isn't. But since "the lee bow effect" is *******s anyway and, if these forums are to be believed, cruisers call THIS the Lee bow effect, then why argue over semantics? Know your audience toad...
Especially considering I've never met a cruiser yet who can spot a 5 degree shift, let alone one who tacks every five minutes to take advantage.
And as to this not being "the Lee bow effect". Well, no it isn't. But since "the lee bow effect" is *******s anyway and, if these forums are to be believed, cruisers call THIS the Lee bow effect, then why argue over semantics? Know your audience toad...
DJE
Well-Known Member
Whats that thing called when you're on port and you can't quite cross the starboard tacker on the beat so you tack close ahead and to leeward of him and backwind his sails?
toad_oftoadhall
Well-Known Member
I'm saying the lee bow effect does not work EVER and is a total myth.
On a totally different subject, is it quicker to sail to maximise VMG? Yes, and if you have a certainty of what the winds going to do for 12 hours then of course you can factor the effect of the wind created by the tide into any judgements. You could decide which tack will give you the best VMG now and in in 6 hours time at a change in tide on a Channel Crossing where there is no other bias in the wind at all. This could work really well. Or if you have my luck you'll tack for 6 hours one way, tack onto the new tack at change of tide....
....and be badly headed.
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toad_oftoadhall
Well-Known Member
Whats that thing called when you're on port and you can't quite cross the starboard tacker on the beat so you tack close ahead and to leeward of him and backwind his sails?
I've heard it called lee bowing. Are you suggesting that has something to do with the lee bow effect? I do hope not!
toad_oftoadhall
Well-Known Member
Then we are in agreement.
Simondjuk
Well-Known Member
Which type of lee bowing was it that the more seasoned fishermen used to land their catch first and get the best price, the one which doesn't exist or the one which does?
DJE
Well-Known Member
Perhaps a lee bow effect.
"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean—neither more nor less."
LittleSister
Well-Known Member
Meeeow! ;-)
Now you're talking! Tacking every five minutes does so interrupt one's tea/G&T drinking, snoozing, chatting, reading, baking, gawping at passing racers...
LittleSister
Well-Known Member
lee + bow + effect = lee bow effect
Are you suggesting that there is no effect from having the tide on the lee bow, as opposed to having it on the windward bow?
toad_oftoadhall
Well-Known Member
Assuming this isn't a trick question then YES, relative to another boat on the same patch of water, being on different tacks will give neither a VMG advantage regardless of what the current is doing.
Imagine 2 boats middle of the pacific. Beating upwind 10 boat lengths apart. They can't tell, but there's 2 knots of current on. Which one's getting the better VMG?
Yup, both the same.
To put it another way, there is no lee bow effect.
If you know otherwise, just post a credible article that explains why one of those two boats out performs the other and everyone will have learned something. Certainly I will have.
flaming
Well-Known Member
But Toad, they're not talking about that Lee bow effect! The one that doesn't exist.
This thread is about what happens to the true wind at the change of the tide.
Since the way to get the best of that is to keep the tide on the Lee bow, I'm sure you can see that calling it "the lee bow effect" is a nice easy way to remember it.
Bringing the debunked "I get better VMG when I pinch to get the tide on the other side of the keel" debate into this thread has just been irrelevant. That's a different discussion, and one in which we clearly agree.
This thread is about what happens to the true wind at the change of the tide.
Since the way to get the best of that is to keep the tide on the Lee bow, I'm sure you can see that calling it "the lee bow effect" is a nice easy way to remember it.
Bringing the debunked "I get better VMG when I pinch to get the tide on the other side of the keel" debate into this thread has just been irrelevant. That's a different discussion, and one in which we clearly agree.
NDG
Well-Known Member
Thanks - That's essentially what my original question was about. I wasn't trying to start a debate about whether the lee bow effect exists.
toad_oftoadhall
Well-Known Member
There is only one lee bow effect. It's a well used term and well documented. If you think otherwise please cite some credible sources stating that there are two meanings.
Using completely the wrong name for something is never going to be a good way yo remember something! It's a recepie for confusion, it's also misleading. All we're talking about here is biasing to the best tack for an unusualy steady anticipated wind. Something all sailors do anyway. To take your 20 degree lift example - who the hell is going to sail for long on the headed tack? They're going to bias their tack without needed to think about it.
It's a well known topic. I don't think *anyone* would incorrectly start a thread with the title 'lee bow effect' if they weren't intending to <cough> polarize opinion somewhat!
NDG
Well-Known Member
It's a well known topic. I don't think *anyone* would incorrectly start a thread with the title 'lee bow effect' if they weren't intending to <cough> polarize opinion somewhat! [/QUOTE]
That's pretty disingenuous. I think it's plain from my question that I was genuinely seeking some informed opinion about what effect the tide has when gybing downwind. You might hold strong opinions on the matter but that doesn't mean the rest of us can't have a civilised debate. If you look back over the thread i think you can see there has been an interesting discussion and I am better informed for it. Being rude to people you disagree with doesn't add much to the dialogue.
[/QUOTE]That's pretty disingenuous. I think it's plain from my question that I was genuinely seeking some informed opinion about what effect the tide has when gybing downwind. You might hold strong opinions on the matter but that doesn't mean the rest of us can't have a civilised debate. If you look back over the thread i think you can see there has been an interesting discussion and I am better informed for it. Being rude to people you disagree with doesn't add much to the dialogue.
shaunksb
Well-Known Member
This is exactly how I see it too.
Perhaps our language may eventually evolve into this specific meaning...
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toad_oftoadhall
Well-Known Member
I'm sorry, it was absolutely not my intention to be rude or uncivilized. Let me know anything you think was rude and I'll reword it tonight.
bbg
Well-Known Member
Please, provide us with this very clear definition.
toad_oftoadhall
Well-Known Member
Both these links define the lee bow effect:
http://www.j105.org/docs/noleebow.pdf
http://www.destinationonedesign.com/prep/index.aspx?chapter=ef1a1d70de9643908888312af7e7952c
I'd love to read some alternative definitions from credible sources, but all the stuff I can find with google (I've posted a lot of links in this thread!) agrees with what I consider the generally accepted definition that's been knocking around all my life.
NDG
Well-Known Member
The subject of lee bow effect has clearly been discuss before. What I haven't found - and I have looked - is a discussion about the effect (if any...) specifically when running. So in that context I think it is a subject that hasn't been discussed in any depth before, and I take some small exception to the implication that I started the thread as some sort of troll.
When you say things like this
Some people might think it is a bit rude....
When you say things like this
Some people might think it is a bit rude....