Over the past several years, Adam Farkas (Assistant Chief Handicapper) has been reviewing our current system for applying credits and penalties for sail sizes.
On November 11th, he presented his findings and suggestions to a sub-committee of the Central Council for review, comment and consideration at the Central Council meeting on November 17th.
A copy of Adams original Sail Area algorithm is available here.
After review, it was found that some modifications to his proposal would be required.
The main findings were as follows:
- Our sail area calculations appear to be grossly overstated when compared to IRC, ORR, UK and ISAF.
- The current formula for calculating adjustments to handicaps for boats with a bowsprit is inaccurate
- Effectiveness of an Asymmetrical needs to be based on the use of an Articulating Bowsprit or a Non-articulating Bowsprit.
- Adjustments for sail size needs to be based on the as designed "Standard Equipment" that the manufacturer supplied.
Central Council approved a two year plan for implementing the changes to our formula for calculating Spinnaker size and adjustments. They are also cognizant of the fact that some of these changes may impact individual boats ASP and are committed to review the class SP for those affected.
Phase 1 - Implementation for 2013 sailing season
- Redefine the definition of the JSP to represent the manufacturer supplied spinnaker pole or bowsprit pole.
- Redefine the definition of the ISP to represent the manufacturer supplied spinnaker hoist.
- Simplify the Spinnaker formula to be consistent for both the Symmetrical and Asymmetrical sail.
- Update the current "Flying Sails" formulas to use the JSP and ISP
- Correct the formula for calculating penalties for oversized bowsprit poles
- Introduce a "Centreline" tacked spinnaker credit for boats that do not carry either a spinnaker pole or articulating bowsprit pole on board.
- Re-class boats that added a Bowsprit and/or Asymmetrical Sail which required a "MOD" designation, back to the standard class.
- Begin asking for the "Foot" measurement of the Symmetrical spinnaker (to be used in 2014)
- Notify members of the discontinuation of the "Grandfather Credit" in 2014
Phase II - Implementation for 2014 sailing season
- Modify the Asymmetrical Luff measurement to equal (Luff + Leach) / 2
- Begin using the Standard Class Sail Area formula:
SAstd = 1.8 * .79 * JSP * (ISP2 + JSP2 ) ^ 0.5
- Begin using measured Sail area calculation for Symmetrical spinnaker:
SAsym = .83 * MLL * (Foot + 4 * MG) / 5
- MG to be the greater of MG or 1.8 x SPL
- Use Symmetrical MG for any unmeasured foot in our database.
- Begin using measured Sail area calculation for Asymmetrical spinnaker:
SAasym = .83 * AML * (Foot + 4 * MG) / 5
- MG to be the greater of MG or 1.8 x SPL or 1.8 x BSL
- Use measured Sail area against Standard Sail area to find SA%
- Replace SA% for G% in our adjustment table
- Discontinue "Grandfather Credit"
Modifications to the Handicappers Manual are available for previewing on-line at: