Measuring Up

Handicapping Formula

Our handicapping fomula is based on the 1974 Off Soundings Club Rating Rule:

Rated Length=[ {L + (2 * √MSA * RA)} / 2.5 ]*PA
where L=PL +/- BC
PL=( LOA + LWL ) / 2
BC=2 * ( LOA / 4 – beam )
MSA=Measured sail area
PA=Propeller Allowance
RA=Rig Allowance

The critical elements of this formula are the boat’s dimensions, sail area, prop and rig type. Measured Sail Area is the theoretical area available for lowers, and reflects the rig type and size, not the boat?s sail inventory. There is no provision for spinnakers, topsails, etc. so boats carrying these sails have an advantage.


Classes are determined by rated length before penalties or credits are applied. (The race committee reserves the right to determine classing by rig, displacement, performance or other criteria, as well as rated length.) Classes have changed over the years, as has the course length for each class. Large classes may be split.

Thimble Shoal Fleet (118 nm course)
Class AA rates 50 feet or more
Class A rates from 40 to less than 50 feet

Windmill Point Fleet (83 nm course)
Class B rates from 30 to less than 40 feet
Class C rates less than 30 feet


In 2017 the GCBSR changed over from using a Time-on-Distance (TOD) formula for corrected time calculations, to a Rating Factor (sometimes confusingly called Time-on-Time (TOT)). This type of rating is better for long distance races that can have highly variable winds. The Rating Factor is based upon the Rated Length of the vessel through this formula:

Rating Factor = √Rated Length / √40

The rating factor is then further adjusted each year based on the cumulative performance of the vessel in all previous races in order to develop an accurate handicap for each vessel. The Rating Factor has been calculated for every boat that has participated in the Race since 1999. Boats of similar Rating factor should perform similarly.


This is a fun race, so a penalty is applied to prior winners to help prevent the same boat from winning year after year:

First in class: 10% penalty in her next race
Second in class: 5% penalty in her next race

If a schooner does not start in a given year, her penalty carries forward until she races again.

The race committee reserves the right to make appropriate adjustments in allowances or class placement until the vessel becomes competitive. The first time a schooner competes, she normally races without adjustment. The vessel’s previous performance will be used to adjust the vessel’s rating. If you question your rating, please review the issue with the race committee.


The calculation for corrected time is simply:

Corrected Time = Elapsed Time * Rating factor

Vessels with larger Rating Factors will wind up “owing time” to vessels with a lower Rating factor.  The list of current Rating factors for schooners that have raced in the past 20 years can be found here.