I don't think that is necessarily true, but I might be misinterpreting something. I will grant you that when wind direction and even wind speed changes, you must react by trimming sails to the tell tales. That's a given. BTW, I basically sail with reference to land marks rather than a compass, and wind direction is in a near constant flux that can vary up to 45 degrees on a normal day and up to 90 degrees on the more frustrating days. :cussing: That shapes my opinion on the uselessness of both a compass and true wind.
But, as you know, apparent wind direction is a vector that is determined by the true wind direction, true wind speed and boat speed for any given course direction. Any change in one of those 3 components is going to affect the apparent wind.
So when you are happily charging along at a fast boat speed and tell tales streaming, what happens when the wind speed suddenly increases? The apparent wind moves aft in my experience and it shows up on the wind instrument as it is happening. Since I am watching where I'm going primarily and checking sail trim secondarily (in single-hand sailing mode) I can sense by the wind and my observance of sail trim what is happening and the instrument basically confirms. Where it may have been 40 degrees before it may read more like 50 degrees, while my boat speed has been constant and the tell tales are still streaming.
BTW, I don't see how hysteresis applies since the instrument has no memory of past input and there isn't a lag between input and output. The instrument shows changes in real time.
This may be where I might be misinterpreting ... I see the apparent wind moving aft as a signal that the increased wind speed is actually giving me a lift, and I typically react by pinching up to take advantage. Now if I glance at the instrument to confirm, and I'm quick about it, I can adjust while the tell tales are still streaming. It is far quicker for me to react at the helm than it is to trim sails, since I don't have a sail trimmer. But am I wrong that the increased wind speed actually provides a lift? I may be reacting incorrectly by pinching, thus the sails stall and I have to react by dropping down to regain the correct air flow (which I find to be a common occurrence).
If that is the case, then I can see where apparent wind is misleading. Honestly, it is difficult to sort those types of reactions out when there are no other boats to gauge and the wind is shifty and gusty on a normal basis to begin with.
I find that sailing after dark most often provides for the most stable air flows. Thus, setting the trim and holding a consistent speed is simpler! Also, the water is flat and smooth, not like a washing machine!
Scott,
Everything I wrote in reference to this quote.
I must be missing something because I can always tell when I'm lifted or knocked by watching the wind instrument. I trim sails according to the tell-tales, but the wind instrument seems to provide more useful information when set to apparent wind than true wind.
When I'm lifted the apparent wind shifts aft and I can see it on the wind instrument instantly. When I'm knocked the opposite happens. When a puff increases wind speed, the apparent wind shifts aft and gives me a lift, which I can see instantly. In a lull, apparent moves forward so I can tell easily when I'm going to get knocked as a result.
Some of the new stuff you wrote differs from this, so I'll try and fill in the gaps.
I basically sail with reference to land marks rather than a compass, and wind direction is in a near constant flux that can vary up to 45 degrees on a normal day and up to 90 degrees on the more frustrating days. :cussing: That shapes my opinion on the uselessness of both a compass and true wind.
Actually try and do just the opposite. When the breeze is shifty, more than ever you should sail with a compass and on the lifted board. A big knock can allow you to tack and sail right or close at the destination (or mark).
But, as you know, apparent wind direction is a vector that is determined by the true wind direction, true wind speed and boat speed for any given course direction. Any change in one of those 3 components is going to affect the apparent wind.
That's true, but I never said anything to infer otherwise?
So when you are happily charging along at a fast boat speed and tell tales streaming, what happens when the wind speed suddenly increases? The apparent wind moves aft in my experience and it shows up on the wind instrument as it is happening. Since I am watching where I'm going primarily and checking sail trim secondarily (in single-hand sailing mode) I can sense by the wind and my observance of sail trim what is happening and the instrument basically confirms. Where it may have been 40 degrees before it may read more like 50 degrees, while my boat speed has been constant and the tell tales are still streaming.
You should first try and turn your model around, trim first, watch where second. You are going at a fast walking pace. That land 1/2 mile away is not going to sneek up on you. ;^)
Yes more pressure (puff) pushes AW aft. The ideal model is (every speed maven sing along here)
Ease OFF, Turn UP, Trim IN. That's the fastest, because the sails can respond MUCH faster then the angle of the boat. But if you can only come up, that's better than doing nothing.
You don't need your wind instruments to tell you are getting hit with a puff. Watch for it on the water, feel it in the sails.
BTW, I don't see how hysteresis applies since the instrument has no memory of past input and there isn't a lag between input and output. The instrument shows changes in real time.
That's not correct. No modern instrument (speed, wind, depth) has its dial directly tied to sensor input. With a CPU they all 'smooth' the data; a rolling average over time. That's basically the textbook definition of hysteresis. Many let you select the amount of smoothing, but is always there. So it is ALWAYS behind real-time. Always.
This may be where I might be misinterpreting ... I see the apparent wind moving aft as a signal that the increased wind speed is actually giving me a lift, and I typically react by pinching up to take advantage. Now if I glance at the instrument to confirm, and I'm quick about it, I can adjust while the tell tales are still streaming. It is far quicker for me to react at the helm than it is to trim sails, since I don't have a sail trimmer. But am I wrong that the increased wind speed actually provides a lift? I may be reacting incorrectly by pinching, thus the sails stall and I have to react by dropping down to regain the correct air flow (which I find to be a common occurrence).
What you are describing is a velocity lift. A 'true' lift is a wind shift, either permanent , oscillating, or random. It might be associated with a speed change, but but no means always. To that you just get lifted or knocked as you sail with correct close hauled trim.
Also, if you get a 10 degree knock and do nothing, your inside telltail will go crazy and you might start luffing. If you get a 10 lift and do nothing, the inside will be OK and the sail will fill, but the outside is stalled and you are basically reaching on closehauled sail.
Oh, my comments are made from the prospective of someone that races a lot and puts a lot of thought and effort into sailing performance. When I said 'slow' before that was not a pejorative or personal comment, just a technical assessment. There are days when I set the AP on wind track mode, slightly overtrim the sails and crack a beer too!
