Instruments set to True or Apparent wind?

[Dockhead]

My wind displays (B&G Triton) show both at the same time, and I find that useful. Obviously you sail to Apparent except downwind, but True is very useful for tactics. The autopilot automatically switches to True on a broad reach (when in wind mode obviously) . Apparent is meaningless when sailing very deep, and can get you into an accidental gybe - beware. Just not having wind instruments is also no solution to this - your windex is also useless near DDW if you have any speed on.

Accurate true wind is very useful so in my opinion it's worth making some effort to have accurate STW. I use an Airmar ultrasonic speed log, but a good paddlewheel cleaned and calibrated often is also OK.

[donradcliffe]

I would have to say that apparent wind is more important thnt true when you are trying to prevent accidental gybes. Its the apparent wind that's going to catch the back of your sail, not some calculated wind.

[Dockhead]

Originally Posted by donradcliffe

I would have to say that apparent wind is more important thnt true when you are trying to prevent accidental gybes. Its the apparent wind that's going to catch the back of your sail, not some calculated wind.

What you say about apparent wind being what catches the sail is true, however -- just watch True and Apparent next time you're sailing DDW. Apparent will swing right around as if you're well off DDW, when True tells you the truth -- you may be only a few degrees off. When True is even a degree on the other side of DDW, then Apparent will swing wildly around.

So it's true that it's apparent wind that gets you, but it's True and only True which tells you how close to gybing you are. If you're watching Apparent, you can't see how far you have to go before you gybe. Watching True, you can.

This effect is stronger, the faster your boat is. There won't be as much difference with a heavy boat which is slow downwind. But on a lighter, faster boat, the difference is profound.

[DotDun]

Originally Posted by Dockhead

My wind displays (B&G Triton) show both at the same time, and I find that useful. Obviously you sail to Apparent except downwind, but True is very useful for tactics. The autopilot automatically switches to True on a broad reach (when in wind mode obviously) . Apparent is meaningless when sailing very deep, and can get you into an accidental gybe - beware. Just not having wind instruments is also no solution to this - your windex is also useless near DDW if you have any speed on.

Accurate true wind is very useful so in my opinion it's worth making some effort to have accurate STW. I use an Airmar ultrasonic speed log, but a good paddlewheel cleaned and calibrated often is also OK.

Use SOG to calc TWx ??

[Dockhead]

Originally Posted by DotDun

Use SOG to calc TWx ??

If you use SOG, then you get Ground Wind, not True Wind, and Ground Wind is profoundly non-useful in tidal waters.

[DotDun]

Originally Posted by Dockhead

If you use SOG, then you get Ground Wind, not True Wind, and Ground Wind is profoundly non-useful in tidal waters.

You guys with tidal currents....

I'll bet my speed wheel is off by more than any currents I encounter.

[caradow]

Originally Posted by Dockhead

What you say about apparent wind being what catches the sail is true, however -- just watch True and Apparent next time you're sailing DDW. Apparent will swing right around as if you're well off DDW, when True tells you the truth -- you may be only a few degrees off. When True is even a degree on the other side of DDW, then Apparent will swing wildly around.

So it's true that it's apparent wind that gets you, but it's True and only True which tells you how close to gybing you are. If you're watching Apparent, you can't see how far you have to go before you gybe. Watching True, you can.

This effect is stronger, the faster your boat is. There won't be as much difference with a heavy boat which is slow downwind. But on a lighter, faster boat, the difference is profound.

Well I agree with some of these statements especially as I stated previously that TWA (if it is accurate) is a fantastic tool to use for knowing when to gybe when DDW. However personally if I watched an instrument constantly like AWA to know when I was too deep I would end up crash gybing frequently. Instead get your head out of the instruments and look around.....feel the boat!!
Also as opposed to what another post stated that a windex is useless DDW I find it more important than anything in pushing a boat hard DDW. In fact when running down a wave I always push even deeper to where the main becomes useless and the only sail that is working is the kite. If you sail like this you will be considerably ahead of anyone who doesn't take these bites. Efficient sailing is NEVER in a straight line. Using an instrument to accomplish this is foolish. This is where sailing by the seat of your pants is important. But this is a cruisers forum so as I said previously I am much happier today when I don't worry about such things.

[44'cruisingcat]

Originally Posted by caradow

I honestly doubt "most" cruising boats wind instruments are accurate enough to really believe TW readings. Therefore AW is fine. However on Race boats with calibrated instruments knowing the TWA when sailing DDW with a Kite is a godsend. Much can be gained when knowing your angles and it will give you a great advantage. Much more difficult than going upwind. At one time in my life TW was very important.....now I don't care and much happier.

Sailing very deep angles with the "white sails" I always used TWA. With the assymetric kite, I found the ability to drag the apparent wind so far forward made it necessary to use AWA.

[caradow]

Originally Posted by 44'cruisingcat

Sailing very deep angles with the "white sails" I always used TWA. With the assymetric kite, I found the ability to drag the apparent wind so far forward made it necessary to use AWA.

Yes I would certainly agree with what you have said however specifically in sailing angles with an asym.
I think the difference lies DDW with a symmetrical which is different.
Doesn't it relate to the best VMG for the particular boat you are sailing?
Anyway that's what I think.....guess thats why sometimes you win ...sometimes you loose.