Transpac to incorporate weather into ratings

The Transpac race will now incorporate weather into their rating system.

TPYC has adopted a rating system that incorporates weather predictions at the recommendation of the club’s technical committee following their analysis of previous race data.

The 2025 Transpacific Yacht Race will employ Time-on-Time Forecast Time Correction Factor (F-TCF) ratings calculated from the polar performance data from each boat’s ORR certificate and weather predictions available on the morning of each start. Weather-adjusted ratings computed for each start day maximize the chances for each division to compete fairly against the entire fleet.

The first two days of Transpac are the most likely to have weather conditions that vary between the starts, which are staggered with three starts over five days, as boats work their way out of coastal waters and deal with potentially very different “Catalina Eddies”. F-TCFs created on start mornings account for this variability in the early going. Farther offshore, boats are expected to encounter the trade wind reaching and running conditions Transpac is known for.

Stan Honey, who worked with the TPYC Technical Committee and US Sailing’s Head of Offshore Ratings Jim Teeters in the proposal for and development of the F-TCF scoring system, observed: “Overlays of HRRR forecasts with fleet tracking and satellite imagery for previous races has confirmed that the HRRR does a good job of forecasting the Catalina Eddy. Given the dramatic and varying effects that the Eddy has on the different Transpac starts, by using these forecasts the F-TCF system can reduce the likelihood that the starters in an unlucky day fall out of the running for fleet results the first day of the race.”

See: https://transpacyc.com/news/article/transpac-announces-rating-system-that-incorporates-weather