apparent wind

Say your in your car in a big flat field sitting still.
The wind is coming from the drivers side at 25 mph and blowing straight across the car to the passenger side. A flag on the roof of the car will be streaming to the passenger side. As you pick up speed the flag will start to point more to the rear of the car. When the car is at the same speed as the wind "25" the flag will point at 45deg. to the rear of the car.
Sails "feel" apparent wind, as the boat speeds up the apparent wind starts moving forward. You ether sheet in of turn down wind to keep the tell tails streaming.

1 yes
2 no

skarr1 wrote: Say your in your car in a big flat field sitting still.

Steve, i was trying to take a survey of how many people feel they understand and can utilize apparent wind.. not an explanation of it...

Yes I understand
No, could use help in utilizing it better.

Kind of like hooking up to sail down wind fast, I know how it is done but doing it consistently is another story.

Sorry Andrew, for misunderstanding.

1. yes
2. yes

edited by: skarr1, Sep 21, 2009 - 06:20 PM

motorcycle forums have these looping discussions about counter steering, (the need to PUSH the left side of the bar to instigate left turns)

my own point of view is that understanding the physics of these things is basically irrelevant as you soon work out what works and what doesn't and then do what works

the difference between sailors is generally who can make what they have work the best

not who can understand the physics of what is happening

1. no
2. no
3. I agree with erice

1) Yes
2) somewhat....

I'll need to ask my old salt father in law about this one. Heard the term but no clue.

1. Yes - because I just received a couple of sweet cat sailing books for last B-day 🙂

2. No, but learning...

And I'd agree w/ Andrew ... this is not "basic" sailing, more intermediate and above.

I respectfully disagree with erice (though I do ride [motorcycles] and get that point well).... sure its not necessary to understand apparent wind theory/application to enjoy sailing, but you can be a better, faster, more efficient skipper by knowing the details and physics behind it (same with sail shape and how the wind moves around the sails on a sloop creating lift). Ive sailed little sunfish and FJ's for years and didnt really know about these and it was fun. But now i feel i can move faster in more types of wind and different points of sail by understanding the stuff better.

just my 2 cents 🙂

1. Do you understand the principals of apparent wind?

Yes

2. Do you feel you know how to utilize apparent wind in your sailing

No

I've sailed on and off for a while, and have no issue using the wind to get the boat to go where I want to go (wasn't always true). I bought an H18 this summer and did a lot more sailing with my kids. For me theory comes first, and while I've read a lot, every time I go out, I learn new things and get better; translating the book knowledge into something useful and repeatable.
I'm having a great time, but still making some seriously basic and funny mistakes (hull plugs anyone?). Definitely a beginner and thinking my way through lots of situations as opposed to having practiced and working on fine-tuning.

skarr1 wrote: Sorry Andrew, for misunderstanding.

No worries at all....

erice wrote: understanding the physics of these things is basically irrelevant as you soon work out what works and what doesn't and then do what works

the difference between sailors is generally who can make what they have work the best

not who can understand the physics of what is happening

I totally agree with the caveat that the key phrase is "basically irrelevant as you soon work out".. meaning.. the theory becomes irrelevant after you work it out.. before hand it can be interesting, thought provoking, and of course very confusing.. but when you put theory and practical application together, the theory isn't important...

1. yes
2. yes

andrewscott wrote:
1. Do you understand the principals of apparent wind?
2. Do you feel you know how to utilize apparent wind in your sailing?

edited by: andrewscott, Sep 21, 2009 - 05:28 PM

I am surprised by the folks that answered yes to 1. and no to 2.

I would think the more common permutation would be
1. no
2. yes

Anyone who can make a boat go in the direction they want it too should answer yes to 2. at some level because apparent wind is the only wind that is relevant to a moving boat. So in fact they do know how to use the apparent wind whether they understand it or not. Although in thinking about it I guess such an answer requires some understanding of apparent wind, at least at the level of my first statement. Catch 22?
I disagree with the caveat that understanding the physics of sailing is irrelevant. I am biased because I am a bit of a geek but I grew up on small boats and was always an instinctive sailor (just kind of knew how to make the boat go). My ability to make boats go fast and fix trim problems improved significantly when I started racing bigger boats and reading up on sail trim and the physics behind it. My rationale is partly as follows - if you are just depending on "doing what works" without understanding why then you rely on having seen that problem before or stumbling onto a solution. If you understand how sails work you can quickly move to a solution even is you haven't seen that particular trim problem before. There are an infinite number of permutations so the likelihood that you will have seen them all before and remember the solution is small.

hydroghyl wrote: 1. yes
2. yes

Anyone who can make a boat go in the direction they want it too should answer yes to 2. at some level because apparent wind is the only wind that is relevant to a moving boat. So in fact they do know how to use the apparent wind whether they understand it or not.

I disagree with you .. but thank you for your response.

there is a big difference (IMHO) from knowing what the term means (or the principal of it) and how to utilize it. yes apparent wind is always there (like sunlight).. but that doesn't mean you know how to use/harness, maximize and keep your apparent wind peaked (or create electricity from the sun).

there is a method to build your apparent wind speed up (so can you sail faster than the wind speed. this is only possible (to do with control) if you know the methods and technology to put in practice.

It makes for an interesting conversation when exactly can you put theory to practice to your advantage. I answered no to #2 because even though the only wind that matters is apparent wind, and to get where you want to go you therefore make use of apparent wind, I don't feel that I "know" how to make the most of it.

For example, starting on a reach as I pick up speed and sheet in. I'm now sailing close hauled, but really I'm still 90 deg from the true wind and can point much higher. If I don't think about it, I'm likely to tack 90 deg and get stuck in irons, not because I blew the tack but because I started too low and tried to sail straight into the true wind instead of tacking 120 deg or more or turning up before I tack.

Now at one level I'm taking advantage of apparent wind when I sheet in and could answer yes. But I find I still have to think about where the "real" wind is as I'm planning things like docking or running and the extra step in my mind means I'm not fluent and therefore I answered no.

answer:
1)yes
2)getting there
my boat still doesn't have yarn on the rigging, just telltales on the sails
someone told me not to put anything on the rigging, it would keep me from focusing on the sails, which is where the power is. Said the apparent wind being the wind acting on the sails while underway, is best interpreted looking at the telltales, not a fixed point on a non-wing surface. I'm still figuring it out, and need lots more time on the water. So, #2 is a qualified yes

Yes, yes.
I sailed for at least a few years before I was aware of the wind shifting with boat speed. I suppose on a cat there is a big difference, on a 4 knot monohull, apparent is pretty close to the real deal.

you guys are interesting. I wonder if we haven't degenerated into a semantic distinction between where knowing and understanding overlap. Also I admit that it is with a certain amount of hubris that I answered yes to both the original questions.

1. Yes
2. Yes, but only really when reaching and beating (it's pretty easy to understand when you know something about lift). Still haven't quite worked out the physics on exactly where you want your sails to be with respect to the apparent wind while you are running. And I am sure I could tweak things more than I do.

edited by: Wolfman, Sep 22, 2009 - 05:05 PM

great answers guys (and gals if any).. thanks for the honest responses and keep em coming if you haven't already answered...

1. yes
2. partly, I'm just starting to use it. we sailed our H16 on somewhere between a reach and a broad reach. 17.5 knots with 15 knots of wind.

1.Yes- all the books for newbies (me) talk about it and say you must understand it to be an advanced sailor
2.No- there are so many things going on at first but i am trying to get it!