Apparent vs. True Wind Angle

[Tripp Gal]

OK, so I have to ask. Only because I keep getting myself confused. I have read quite a bit about people discussing their upwind performance and their angles on this board, but am not sure if you are talking true or apparent wind angle. What are the "Mac standard" true and apparent pointing angles? Since I don't see a "T" or "App" beside the angle I never can tell as I myself don't own a Mac.

[Frank C]

Excellent question, Tripp Gal. Somehow I doubt that you're the one who's confused.

From my own experience, the best I've ever been able to accomplish in my Mac 26X is 100 compass degrees between tacks. Using an average summer afternoon example for our Bay, winds are roughly WNW, usually 15+ knots. From a port tack heading at 350*, my BEST stb tack would be heading about 250* with reefed main and jib, trimmed "just so." Since trimming in heavy air requires reefed main and some aft centerboard, it can sometimes be difficult to get the boat to tack.

In summary, my understanding is that I'm tacking through 100* on True wind, using reefed main and jib, or tacking to within 50* true. With the 135 Genoa it's worse, 110* or wider, due to it's being sheeted outside the shrouds.

Also, this is using the "heading" to determine angles. If the boat is tracking to lee, then the tacking angle could be much worse "from track to track." I've never tried to measure this - it would probably be disappointing.

[Timm Miller]

The best you can expect is about 55 degrees......you sail on the apparent wind.

[Tripp Gal]

Thanks for the number. Some sailors only have true wind angle, and some only have apparent. We run with both on at all times to keep tabs on polars/targets.

[Frank C]

My wind gauge quit working (corroded deck plug). Without a gauge, I don't know how you could measure against apparent wind. It's absolutely clear what you're able to accomplish on compass headings, and if relatively steady, the true wind direction must be approximately centered between those headings.