tacking outline

[bkw]

anyone know of any good articles on how often to tack to weather mark?
how one would use gps to figure this out?

[capt.stu]

Dave Dellenbough writes about this in his speed and smarts publication. Also Stewart Walkers books are excellent on this subject. There are some tactical guidelines fof when to tack but it depends on the situation your in at the time. Read Walker and you will learn a lot. Thats how I learned to race and it moved me up to the front third of the fleet right away.
Stu

[bkw]

thanks
i ordered the book

[bkw]

well finishing my third book on racing and i still dont see any hard rule on when to tack. assuming there are no wind shifts how do you know how far to go on a tack. i guess i am looking for some kind of formula like using distance angle and speed. it would seem that you could use the gps, vmg and eta to tell you when its best to tack.
any help would be appreciated.

[morganmike]

there is a rule, but I'm no expert ... I remember a Cruising World article (or similar mag) that talked about how to set up a cone of approach for tacking to a mark. To set it up, draw a line from your position to the mark. With the mark as the origin and the line you've just drawn as the bottom of a triangle, mark off a 15 degree line from the mark back towards your postion, then do the same on the other side of the line. You now have a 30 degree wide cone with the mark as the apex.


I got tired of trying to describe it, (plus I've had a few) so check out this pic:

[morganmike]

Honestly, I'm not sure if that angle marked 30 degrees should be 30 or 15. I think 15, with the total angle as 30. Anyway, that sets up your tacking cone, and you tack when you reach either side of the triangle in ever decreasing tacks until you pass the mark. Supposedly this maximizes the advantage of longer tack legs while minimizing the overall distance traveled.

[bkw]

thanks, thats what i am looking for.
anybody else?

[Giulietta]

Morgan

Its 5 degrees each side of the center line. But that is it.

Also the 45º of each tach really depens on his boat.

[Faster]

Don't forget to factor current into your decision making, and the possibility of better (or more favoured) breeze on one side of the course over the other.

The "keep in the middle" philosophy works well in the absence of such factors because if you commit to any one side, subsequent windshifts will either be death or of little use to you. Keeping close to the Rhumb line allows you to capitalize on a wind shift in either direction.

Almost as important as when to tack is how you tack. It's easy to gain a boat length with a slow smooth tack over a boat that is being slammed into the corners. Many people tack their boats too quickly, giving up distance to weather and overly slowing down the boat.

You've bought the right books - as you gain experience you will be better able to appreciate what they say.

[Gary M]

The simple thing to do is follow the leaders until that awkward day when you are out in front and don't know which way to go.

Actualy it depends on whether you can see the mark of not. If you can, then tack on the shifts until you are close and then you must make a tactical decision on how to approach the mark based on your position relative to other boats in your fleet.

If you cannot see the mark then you must time your tacks so that they are about the same duration assuming a true beat. This will get you to a position where you can see the mark then go to option 1.
Monitoring the wind prior to the start will tell you if it is clocking or backing so you can head up the appropriate side of the course.