Q. Explain the requests for sail girths (widths) for mainsails and spinnakers.

A. Requests for sail girths (widths) for mainsails and spinnakers were new for 2020. They were intended then to be for newly built sails only, as the data for those would be readily available to owners from the sailmaker. These sail girths were used for data gathering only and not for ratings in 2020.

Now after two years of collecting data, CRF 2022 has included declared mainsail girths and spinnaker widths in rating calculations.  Boats declaring mainsails girths greater than the previously assumed defaults (unusually big roach profiles) will see their ratings get slightly faster.  Those declaring girths below those defaults will see slightly slower ratings, so it can be to the advantage of boats with minimal roach mains to declare those girths.  Except in extreme cases, the effect on the rating is +/-1 or 2 sec/mi.  The same approach has been taken with spinnaker widths, with declared widths greater than a previously assumed default rating slightly faster under CRF 2022.