Windward Performance - Genuine Tack Angles

[Factor]

Originally Posted by 2Wind

Last month when cruising along side with the Brisbane to Gladstone race fleet, we faced unfavourable conditions off the Breaksea Spit (North Fraser Island) with 5kts of wind and the 3-4 kt Great Australian current on our nose. Our tack angles were more like 120 degrees then.

Be thankful you could tack!! Some of the boats barely moved in hours. Having enough speed to tack would have been nirvana.

Those figures are pretty good, in fact very good, have you thought about joining the MYCQ and doing some of their races, the OMR handicap system will work for you, you may be surprised how well you do.

[belizesailor]

Something that often gets omitted/misunderstood on cats is the difference between "tacking" angle and "sailing" angle. Most production cats have a relatively broad tacking angle (100+ degrees) but can be driven up closer to windward once they build some boat speed.

[smj]

This really sucks as it leaves me with nothing negative to say about Lagoons performance Really good tacking angles, I'm impressed

[2Wind]

Originally Posted by Factor

Be thankful you could tack!! Some of the boats barely moved in hours. Having enough speed to tack would have been nirvana.

Factor, we spent 6 hours drifting with the fleet in dead flat and calm conditions just inside the continental shelf off Breaksea. It was beautiful, but after dark, far too many navigation lights moving around close at hand for my taste. Being in the cruising division, I turned to the iron sail and made way for Lady Musgrave instead of Gladstone - no too much a loss in that destination!

[Factor]

You weren't the only one who turned the engine on. In fact any boat with sufficient fuel on board probably did the same.

[youngson]

ive sailed an old racing cross trimaran with a 5 foot fin keel and it would sail almost directly into the wind, it was pretty awesome.

[StuM]

Originally Posted by youngson

ive sailed an old racing cross trimaran with a 5 foot fin keel and it would sail almost directly into the wind, it was pretty awesome.

Cough! Cough!

[2Wind]

Originally Posted by youngson

ive sailed an old racing cross trimaran with a 5 foot fin keel and it would sail almost directly into the wind, it was pretty awesome.

Although is seems like the you are sailing right into the wind, its just a perception. Take the AC72's for instance, as there is precious little that is faster and can tack. It is said that they can sail at 16 degrees to apparent wind which is phenomenal. That would feel like it is right in your face. Nevertheless, they sail so fast (SOG), more than two times wind speed, that even at angles this close to the wind (apparent), they are still near 40 -45 degrees to the true wind angle. So they still tack through an 85 odd degree arc across the wind, but in so doing, overall, their VMG to windward is fabulous, more because of their SOG rather than their angle of sail.

[belizesailor]

Originally Posted by 2Wind

Although is seems like the you are sailing right into the wind, its just a perception. Take the AC72's for instance, as there is precious little that is faster and can tack. It is said that they can sail at 16 degrees to apparent wind which is phenomenal. That would feel like it is right in your face. Nevertheless, they sail so fast (SOG), more than two times wind speed, that even at angles this close to the wind (apparent), they are still near 40 -45 degrees to the true wind angle. So they still tack through an 85 odd degree arc across the wind, but in so doing, overall, their VMG to windward is fabulous, more because of their SOG rather than their angle of sail.

We used to use a similar strategy racing Corsair tris. SOG is so fast and so much speed is lost during a tack that it is generally a better strategy to focus on maximizing SOG and not worry so much about distance travelled....you can make it up really fast at 20 knots.

And on high performance boats like these, the boat speed generates such dramatic shifts in apparent wind that the sailing angle relative to true wind may not be very close (acute). Apparent wind angle is almost never aft of beam regardless ot TWA (even if its dead down wind). So boat speed becomes the key. Very different than sailing any production cat.

[tomfl]

Originally Posted by belizesailor

We used to use a similar strategy racing Corsair tris. SOG is so fast and so much speed is lost during a tack that it is generally a better strategy to focus on maximizing SOG and not worry so much about distance travelled....you can make it up really fast at 20 knots.

And on high performance boats like these, the boat speed generates such dramatic shifts in apparent wind that the sailing angle relative to true wind may not be very close (acute). Apparent wind angle is almost never aft of beam regardless ot TWA (even if its dead down wind). So boat speed becomes the key. Very different than sailing any production cat.

Not sure what type of electronics you guys have but my Garmin not only has SOG but something called VMG. Matter of fact any race boat I have ever seen has VMG.

I always pay a lot more attention to VMG than SOG. My production Seawind often hits double digits in 15 knots of wind and you can make up a lot of ground at ten knots.

Thought everybody knew in any cat, production or otherwise, you were suppose to fall off till you got the best VMG and ignore SOG.

[2Wind]

[Jim Cate]

In order for visual inspection of tracks to be valid, one must be VERY sure that there is zero current involved. Even fractional knots can embellish (or disfigure!) those angles over the ground to a surprising degree.

But it is fun to look at them, and discard all the ones that look bad!

Cheers,

Jim

[belizesailor]

Originally Posted by tomfl

Not sure what type of electronics you guys have but my Garmin not only has SOG but something called VMG. Matter of fact any race boat I have ever seen has VMG.

I always pay a lot more attention to VMG than SOG. My production Seawind often hits double digits in 15 knots of wind and you can make up a lot of ground at ten knots.

Thought everybody knew in any cat, production or otherwise, you were suppose to fall off till you got the best VMG and ignore SOG.

Gee Tohm, I'm jus an ol' M'sippi boy. Don't know much bout them fancy three letter wurds and new fangled electronic stuff.

[tomfl]

Originally Posted by belizesailor

Gee Tohm, I'm jus an ol' M'sippi boy. Don't know much bout them fancy three letter wurds and new fangled electronic stuff.

No more sitting at the cool kids table for you.

Google is your friend.

But how did you get this far in a thread asking folks to post pix of their GPS plotters if you don't know what GPS means.