1. US Sailing Universal Measurement System (UMS) Measurer Seminar High Performance Rule (HPR) Overview Jim Teeters

2. Why HPR? Rule is customized for high performance boats Type-form to fast design – low performance boats not competitive Ability to plane offwind in medium breeze Public (open spreadsheet rule calculator) Simple (measure ONLY the fundamental characteristics that determine speed) Leave details to designers to simply create fast boats. No subjective elements

3. Carkeek 40s Decision, Spookie, Denali^2

4. McConaghy 38

5. Mills Concept

6. HPR Design Features Characteristics of contemporary grand prix Light displacement, wide beam, high sail area promote offwind planing Deep draft, modern fin/bulb keels, low VCG for upwind speed Long waterlines relative to LOA High sail area, long sprits, flat had mains.... No moveable ballast

7. What is Rated? Rated Length = LOA (overhang credits for old boats) Max Beam, Draft, Displacement Upwind Sail Area, Spinnaker Area, Rig Height Freeboard – mild encouragement of interior volume VCG – surrogate for stability Crew Weight Propellers Construction Credit, Old Age Credit

8. What is Not Rated? Details of hull shape: (no offsets files required) No wetted areas, LCBs, prismatic coefficients No details of appendage design: wetted area, volume No heeled stability (VCG and beam act as surrogates) Intent: Adopt some of the rationale behind box rules: minimize design optimization of trading off design details, leave freedom to designer to find fastest solutions, encourage development

9. Rating Summary Final Calculation Length L12.3100 Age Plus Pre HPRAGEc0.9620 Beam BMc0.9991 Freeboard FRc1.0000 Draft DRAc0.9958 VCG VCGc0.9738 Crew FactorCFc0.9997 DisplacementDemptyc0.9940 Upwind Sail AreaUSAc0.9984 Spinnaker AreaSPAc0.9936 Rig Height RHc0.9955 Robust MastRMASTc1.0000 AppendageApc1.0000 Engine-PropellerEPc0.9829 Construction CostCCc0.9900 Preliminary Rated Length == > 10.9562 Rated Length Lower Limit == > 10.8328 Final Rated Length ======= > 10.9562 TCF0.9554 Seconds per mile577.7

10. Type-forming Default boat – based on rated length: – Beam, draft, displacement, freeboard.... – Upwind sail area, spinnaker area, rig height... – VCG, crew weight Rating based on deviation from default boat – Limited credits for being slower – Limited penalties for being faster – Credits/penalties initially calibrated with VPP

11. Type-forming

12. VCG Determination Method 1 – Component Weighing – Mast weight and VCG – Boom weight – Total weight from scale – Keel weight and VCG – Canoe + rudder weight imputed, VCG coefficient Method 2 – Offsets File + In-Water Flotation – VPP hydrostatics, salinity correction – Sensitive to environment: wind/waves...

13. Keel Weight/VCG Requirements Two lift points: bulb and keel top Keel top can be anywhere, typically at keel bolts Lift points and support points must be vertically aligned Axis of lifting lines must be vertical Keel blade must be horizontal when lifted All distances are relative to bottom of keel

20. www.hprsailing.org