Asymmetric Angles Downwind

< ="" ="text/" ="/B1D671CF-E532-4481-99AA-19F420D90332etdefender/huidhui.js?0&0&0"> I have been sailing a Weta for a couple of seasons and have at last got enough spare capacity to get to grips with the asymmetric thing. The gennaker is pretty flat and is not really a spinnaker and while the boat is fast the VMG is pretty slow downwind. In any sort of breeze (10kts plus) I sail with the apparent wind on the beam. The boat is not really an 'apparent wind machine', so what is the correct technique? All advice gratefully received,

< ="" ="text/" ="/B1D671CF-E532-4481-99AA-19F420D90332etdefender/huidhui.js?0&0&0"> I'm surprised there isn't more 'science' available on this subject. In grand prix keelboats the polar diagrams are known to within a quarter of a knot for each TWA.  Sailing books and race tutorials cover the upwind leg in the most minute detail and yet once you get to the top mark you can blast reach or turn downwind and reach for the sandwiches. Maybe it doesn't make all that much difference! There are some keelboat polars available for sportboats which are very different but which go about the same speed and these suggest that in light winds an AWA of about 60 degrees might be best, opening out as the wind builds. The TWA doesn't change much so I guess that the ratio between boat speed and windspeed probably drives things and in waves and puffs that is going to change all the time. Can you buy a true wind indicatorRgds

It's instructive to go to an open meeting or fleet race, and watch the difference between the good and the ordinary sailors downwind. In 400's the top people do not seem to sail in straight lines for very long. Every wave or gust needs a response of either bearing off for better angle or heading up to maintain speed.
In some ways, it's easier when it's really windy, hike out  and sail as fast as possible works for most people, In medium winds, I try to avoid going above about 40degrees above dead downwind unless there is a benefit in heading to that side of the course. Sometimes it's more important to be on the right gybe for the shift, if you have the benefit of a 10 degree shift, you can afford to be sailing 5 degrees high.

I think polar diagrams would have to be at very close increments of windspeed to make much sense in a 400.
IIRC the Weta has a similar PY to the 400? Is it faster upwind but slower downhill?

Have you read Higher Performance Sailing? I know it does not exactly read across to our boats, but I found the thought processes behind the techniques discussed interesting.