Flying the Asymmetrical Direct Down Wind

Oct 29, 2016
1,915
Hunter 41 DS Port Huron
Yesterday during a race in light air <8 on the first down wind leg (wind at our starboard quarter) we flew wing on wing which put us out of the hunt to finish respectfully, round the next mark to a reach and made up some ground but not enough on this short leg, next mark took us to DDW we set wing on wing, but with a 3 mile leg we figure lets see what happens when we launch the Asym, our set up experiment was to run the sheet through a cleat on the forward quarter and I will be a monkeys uncle the darn thing filled and stayed filled as long as I maintained 5* either side of 180* true and the boat sped up to almost 7 with a 8 knot wind + a 1 kt current. Everything I have read says an Asym just won't fly on a DDW course but it does and sooooooo much better than wing on wing on our 41DS.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
Where was the apparent wind? That’s what the sail “sees”. Did you have instruments?
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
What did you mean by
as long as I maintained 5* either side of 180* true
Where was the mainsail?
Were you flying main and asymm wing on wing? With a whisker pole.
If so, you were probably using the asymm in pure push (parachute) mode, rather than generating lift.

You can use an asymm Ddw in push mode, but that’s usually not the fastest way to get down wind.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
I just did the math.... for true wind of 175 degrees, boat speed of 7 , and true wind speed of 8 kts, the apparent wind speed is 1.2 at 144*. . An Asymm that’s cut for deep angles will fly at AWA of 144*.
 
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Oct 29, 2016
1,915
Hunter 41 DS Port Huron
Yes the main was on the other wing (port side), we were running a almost 7 with an 8 kt wind, with our VMG matching our VOG, not sure how you could get much faster than that. My point was more to the fact that we were actually able to fly the Asym DDW where I have attempted in the past and failed, we believe that this was due to running the sheet through a block tied to the forward quarter docking cleat changing the sheeting angle relative to the clew.
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
What instruments were you using to measure angle, wind speed, and boat speed through the water?
 
Oct 29, 2016
1,915
Hunter 41 DS Port Huron
The Sapphire is outfitted with a full compliment of Raymarine instruments, wind instrument st60