Read the Feb 16 report and scroll down to: 3. How to reduce the gap between the Dart 18 and Dart 18 cat boat? to understand the thinking on singlehanded sailing.
http://schrs.com/news.php Thanks for the pointer. Unfortunately, it doesn't help me out. The discussion there is changing the ratings of underpowered main-only boats. The Isotope is a somewhat overpowered sloop-rigged (main and jib) boat and is not affected by the change. By the way, the Dart 18 solo was rated 2:13 SLOWER than a Dart 18 in an hour long race. The change makes it only 0:38 slower per hour. According to my calculations, the Isotope single-handed would be rated 6 minutes FASTER than an Isotope 2-up in a 60 minute race. That's a 10% difference. Portsmouth Yardstick has the Isotope 1-up a bit less than 5% faster than 2-up. 5% seems to be reasonably accurate given a long history of the same pool of sailors racing in both configurations (that is, there isn't a big difference in skill between the racers).
If I have to race SCHRS under those ratings, I'll race 2-up.
By the way, what happens if a Hobie 16 sailor races single-handed? Does he get to use the same SCHRS rating (1.91) or does he have to recalculate (1.117)? That's 4 minutes (over 6.5%) in an hour long race.
