True Wind Angle for the Kite

[Thomas Leith]

Hey there --

New Viper sailor here. This coming weekend there will be a sort-of steeplechase race around the lake. What's the highest true wind angle we can expect to fly the kite?? I want to try to do a little race planning <gasp!>.

It seems to me 120 TWA should be do-able and 150 TWA is probably as deep as we want to go.

Wisdom?

[Kay VanValkenburgh]

I've got no clear answer for you. Trust no one who does....

Everything depends on windspeed and hiking power. Polar charts would get quite complicated, because they would need to take both things into account, not to mention heel and wave state (assume flat is fast, but you'll find some differences; and btw is wave state a bigger percentage-wise differentiator among boats planing downwind than among displacement boats making the slog?).

General observations: in light air and flat water, you can sail very high with the kite. You'll get nothing scientific from me like actual polars - expect only nonsense, in fact - but if you suddenly find yourself low of a gybe mark you'll certainly be able to reach above 90 TWA in under 8kts. In very heavy air (say 30kts just for grins), you'll be lucky to do anything but ddw.

Anyone have a formula? If you're serious about even a little race planning as to when you'll hoist and when you'll go NFS, it's probably time to break open Frank Bethwait's tome, comb the index, and do some intensive math!

[Thomas Leith]

Thanks for the reply.

We were out in flat water (inland lake) in 12 -> 15. Wind was out of ~250 and the mark was at 360, or ~110 TWA. This was a 3.5 mile leg with shoals on the right precluding the low route. Really couldn't hold the kite at 110 TWA, and I thought we were being pulled leeward too much even though the bow was pointed the right way. We ended up dousing the kite and going across on the jib. Next time I think it'll be faster to take a beam reach hitch on the jib up the the point where we can fall off to sail 130 TWA to the mark with the kite. Can't wait to try it...