EatChips said:Just sailed at my local club in very shift conditions and got badly beaten. I always like to do a post-mortem after I sail. My conclusion was that I was tacking almost every time I got headed on the wind BUT I was tacking before the wind oscillated past its mean/median/average position. ie I was sometimes actually tacking away from the lifted tack onto the headed one!
So...my problem is... I do not sail with a compass and the very top guys don't either so how do they work out the mean/median/average wind direction to work out whether they are on a lift or header. The default cries are: use the land or use other buts BUT the the you surely cannot use the land as you are moving relative to it AND how can other boats help me with the mean/median/average wind direction?
Fellow Laserites - please help?
They are correct. You should look at the land and the direction of your bow relative to the weather mark. You are also correct in that your land marks will change as you sail up the course. Just keep up with them and you can follow the ups and downs. If you are lake sailing this is usually a lot easier to do than sailing in open water where land marks may be too far away to get a good sight on. Also, don't tack every time you get a header. Count to 10 and see if it holds before tacking. Sometimes if the breeze is up and down in velocity you'll get a "velocity header" which means you've just sailed into less breeze. If this happens change gears keep the boat going forward and see how your course settles out. If the breeze comes back your heading should too. Also, in lighter air the tacking angles become much wider. Once you get the hang of driving the boat better and measuring lifts and headers w/out a compass then you can get a compass and try sailing with your head a little more "in the boat". If you're just getting started get the basics down first.
Rob B said:EatChips said:Just sailed at my local club in very shift conditions and got badly beaten. I always like to do a post-mortem after I sail. My conclusion was that I was tacking almost every time I got headed on the wind BUT I was tacking before the wind oscillated past its mean/median/average position. ie I was sometimes actually tacking away from the lifted tack onto the headed one!
So...my problem is... I do not sail with a compass and the very top guys don't either so how do they work out the mean/median/average wind direction to work out whether they are on a lift or header. The default cries are: use the land or use other buts BUT the the you surely cannot use the land as you are moving relative to it AND how can other boats help me with the mean/median/average wind direction?
Fellow Laserites - please help?
They are correct. You should look at the land and the direction of your bow relative to the weather mark. You are also correct in that your land marks will change as you sail up the course. Just keep up with them and you can follow the ups and downs. If you are lake sailing this is usually a lot easier to do than sailing in open water where land marks may be too far away to get a good sight on. Also, don't tack every time you get a header. Count to 10 and see if it holds before tacking. Sometimes if the breeze is up and down in velocity you'll get a "velocity header" which means you've just sailed into less breeze. If this happens change gears keep the boat going forward and see how your course settles out. If the breeze comes back your heading should too. Also, in lighter air the tacking angles become much wider. Once you get the hang of driving the boat better and measuring lifts and headers w/out a compass then you can get a compass and try sailing with your head a little more "in the boat". If you're just getting started get the basics down first.
Thanks Rob. I have been sailing for quite a few years now and am normally at the right end of the fleet. I'm just thinking about things from first principles again. Your advice was to use landmarks and not to be too quick to tack... so when you sail, would I be right in assuming that you would only be sure whether you are on the lifted or headed tack to the nearest 5 degrees? - Thanks again.
EatChips said:Thanks Rob. I have been sailing for quite a few years now and am normally at the right end of the fleet. I'm just thinking about things from first principles again. Your advice was to use landmarks and not to be too quick to tack... so when you sail, would I be right in assuming that you would only be sure whether you are on the lifted or headed tack to the nearest 5 degrees? - Thanks again.
EatChips said:Rob - all really clear less your comment about persistent shifts. I assume you meant keep on the header if you thought that the shift was going to be persistent?
Thanks,
Peter
While the above may be true under perfect conditions (in the middle of open water with no land influence) and a specific weather condition, I don't think that is a very good method for deciding which tack to be on. There are too many variables that effect what the wind will do on the race course and one needs to pay attention to the effects, at that point in time on the course, that are having the most influence on the wind speed and direction. In other words, get your head of the boat and look around. For example, one needs to learn to read puffs on the water and wether they will be headers or lifts. Learn how to position yourself to take advantage of the shifty type of gusts that are characteristic of offshore breezes. Learn how to time shifts in an oscillating breeze. Learn how to tell the diff between a persistant shift and an oscillating shift (and when to treat an oscillating shift as a persistant shift on the beat or run) There's more to it that that, but I'm really trying to point out that it's not as simple as being on port tack when a gust comes.emilebr said:hi,
It's also important that you sail on port tack if you see a gust coming (if you are sailing on the Northern Hemisphere). Then you can sail a better course on the upwind reach. But if you are sailing on the Southern Hemisphere it's better not to sail on port tack, when there is a gust coming. That has to do with the direction of the current of the low pressure area.
(sorry for bat english)
EatChips said:......So...my problem is... I do not sail with a compass and the very top guys don't either so how do they work out the mean/median/average wind direction to work out whether they are on a lift or header.....
49208 said:While the above may be true under perfect conditions (in the middle of open water with no land influence) and a specific weather condition, I don't think that is a very good method for deciding which tack to be on. There are too many variables that effect what the wind will do on the race course and one needs to pay attention to the effects, at that point in time on the course, that are having the most influence on the wind speed and direction....
Are you talking about the Coriolis effect ?emilebr said:It's really true what I said, and it works always, even on the very small lake where the marina is. My trainer has learned me that, and he will know it best, because he got a fifth place on a worldchampionship of the Europe class.....
It seems to be it is that force, but from physicists I learned: For the direction of the turning of little whirlpools at the drain of a shower, it is independend if you are at the south or at the north of the globe. All depends of micro disturbances of the surface areas around that whirlpools, they say - although 99,99...% of the whirlpools (and also lowpressure areas of the weather) turn against the clock on the north of the globe.49208 said:Are you talking about the Coriolis effect ?