Lee Bow Effect.

Mark-1

Mark-1

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An article in PBO has reminded me of a recurring debate from my youth.

I don't think I've seen it discussed here and if the heated discussion from my youth are anything to go by, it could really catch fire as a topic on YBW.

Gentlemen, please debate the following assertion:

"The lee-bow effect is an illusion, and does not exist."

I'm not saying where I stood on the subject.
 
This has been ranted on, on the Y&y forum.

Some people have different ideas about what other people think the lee bow effect is and say the others are wrong.

I think a lot of people find it hard to work with vectors and a lot of discussion at cross purposes ensues.
 
Seems a very simple thing to me, you either enjoy lee bow ( current / tide ) effect or you don't, tactics to employ it seem straightforward to me, but then I don't have my ideas perverted by racing ! :D
 
Mark-1 said:
"The lee-bow effect is an illusion, and does not exist."
Click to expand...
I use it all the time:

  1. Point boat at shore;
  2. Work out what the tide is doing;
  3. Check that the wind is blowing from the shore; and
  4. Tack into the tide and let it push you towards your target, tack the other way and you will go away from your target.
 
Unless your:
- Upwind,
- The tide is set to change during the passage (ideally halfway through)
- There is no land to port or starboard
- You are sailing cross tide

Then it is very difficult to utilize. In my book it is not worth worrying about in the slightest.
 
Mark-1 said:
An article in PBO has reminded me of a recurring debate from my youth.

I don't think I've seen it discussed here and if the heated discussion from my youth are anything to go by, it could really catch fire as a topic on YBW.

Gentlemen, please debate the following assertion:

"The lee-bow effect is an illusion, and does not exist."

I'm not saying where I stood on the subject.
Click to expand...

Tide: On the bow, Lee bow, lee side, lee stern, on the stern, weather stern, weather side, weather bow. They all exist as tide is like being on a moving carpet.

If going upwind a lee bow tide will help in terms of gaining 'height' whereas a weather bow tide will do the reverse, depending on strength, angle of flow, leeway etc. Worth being aware of and utilising if possible. As someone else has mentioned drawing some vectors would set it all out, bit like working out course to steer on a chart.
 
Gorf said:
I use it all the time:

  1. Point boat at shore;
  2. Work out what the tide is doing;
  3. Check that the wind is blowing from the shore; and
  4. Tack into the tide and let it push you towards your target, tack the other way and you will go away from your target.
Click to expand...

I may be thick but isn't that ferry gliding?
 
lw395 said:
Some people have different ideas about what other people think the lee bow effect
Click to expand...

Funny you should say that. The Lee Bow Effect in PBO isn't the Lee Bow effect as I know it at all. (This is, http://www.destinationonedesign.com/prep/index.aspx?chapter=ef1a1d70de9643908888312af7e7952c,http://www.sailingworld.com/experts/current-affairs?page=0,1, http://www.j105.org/docs/noleebow.pdf).

I'm not saying they match my view on the Lee Bow Effect, they just match my view on what the Lee Bow Effect is.
 
There are two meanings (at least) to lee bow effect.

1) When racing, tack just ahead of another boat and about half a boat length to leeward of their course. Difficult to accomplish in a cruiser-racer without a very skilled crew, but very effective if you get it right. The backwash from your main will affect the flow over their sails causing them to fall down below your course. It's much more common for it to be successfully accomplished between dinghies. There's a few counter tactics, but if you really get caught by someone else doing it to you then you're faced with having to tack off.

2) When cruising (or offshore racing) use the tide to free up the apparent wind to allow you to point higher (calculated against the true, or ground, wind) then tack as the tide changes to do the same on the other tack. It does work, but as others have said, often the situation affects how much benefit, if any, you will get from it.
 
To me Lee-bowing is when sailing to windward against a stream (usually tide). If you can just lay the next headland, or turning point - buoy, or whatever it is by keeping the stream on the lee side of your bow you will get there a lot quicker than sailing more full & by with the stream on your weather bow (ie fewer tacks, half of which will take you backwards).

If it's an illusion it's a b****y effective one, that I'll continue to be fooled by.
 
dt4134 said:
There are two meanings (at least) to lee bow effect.
Click to expand...

The meaning described in my links is, as far as I know, the typical meaning. Certainly it's the only meaning I've ever heard widely used, and until today the only one I've ever seen in print.

PBO go with 2), but I can't see how that can be described as an 'effect'.

My brother used to use Lee Bow as a verb so that would fit with 1). (As in, "I Lee Bowed him.")
 
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Mark-1 said:
PBO go with 2), but I can't see how that can be described as an 'effect'.

My brother used to use Lee Bow as a verb so that would fit with 1). (As in, "I Lee Bowed him.")
Click to expand...

I use it as a verb too in sense 1).

For the second sense, you need to understand what the tide wind is (very valuable too when racing if you're into tactics).

Effectively there is a wind caused by the tide. Easiest to comprehend if you imagine a situation where there is no wind at all. A boat being pushed by 3 knots of tide through the still air will feel a tide wind of 3 knots in the opposite direction to the tide.

Now imagine there is a true wind. The 'true' wind actually felt by the boat (and displayed on instruments - providing they're linked to the log and not the GPS) will be a combination or the real true wind and the tide wind.

Do the vector arithmetic and you'll find that if the wind is at about 90 degs to the tide, you will get a freer 'true' wind if you sail with the tide under your lee bow and will be lifted by a corresponding amount.
 
dt4134 said:
There are two meanings (at least) to lee bow effect.

1) When racing, tack just ahead of another boat and about half a boat length to leeward of their course. Difficult to accomplish in a cruiser-racer without a very skilled crew, but very effective if you get it right. The backwash from your main will affect the flow over their sails causing them to fall down below your course. It's much more common for it to be successfully accomplished between dinghies. There's a few counter tactics, but if you really get caught by someone else doing it to you then you're faced with having to tack off.
Click to expand...

I've never heard of that being referred to as Lee Bowing, I have most commonly heard the term dirty winding.

Lee bowing is a definite certainty, I have used it in racing on an incoming tide, in the river to almost ferry glide over the river to the next mark.

Ferry gliding is essentially lee bowing in a sailing yacht.
 
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