Class Rules:

Performance Parameters

Multihull & Monohull

Standards to insure competition between boats of identical design in the essential areas such as hull lines, weights, and sail plan are applied to Ratings. 

      Sail Main Jib Platform Sailing Crew Crew.Min Crew.Max Hiking
    Length Area Vertical.Luff Vertical.Luff Weight Weight Wt./# Weight Weight Trapeze
America’s Cup (AC45, AC72) Link + + + + + + + + + +
F18 Link + + + + + + + + + +
Texel Netherlands ≤ 20 ft. Link + + + +   + + +   +
Texel Netherlands > 20 ft. Link + + + +   + + +    
Texel Australia (OMR) > 22ft. Link + + + +   + + +    
Texel Thailand (OMR) > 22ft. Link + + + +   + + +    
Multi2000 (France) > 22ft Link + + + +   + +      
SCHRS ≤ 20 ft. Link + + + +   + #     +
                       
Antrim 27 Link + + + +   + 2   1100 lb  
J-120 Link + + + +   +     600 kg  
Melges 24 Link + + + + +   3   360 kg  
J-105 Link + + + + +       1045 lb  
Express 27 Link + + + + +       880 lb  
                       
# Texel Crew Weight Assumption x LOA or Declaration
# SCHRS Crew Number Crew Weight Assumption = 75kg / 165 lb each

Multihull Rating Formulas: General Form to assess Performance

100 / (coeff. * RL ^ p * RSA ^ q / RW ^ r).

RL = Rated Length
RSA = Rated Sail Area
RW = Rated Weight
   
TR.NDL = Texel Rating (Netherlands)
TR.AUS = Texel Rating (Australia)
Multi2000 = Multi2000 Rule (France)
MOCRA = Kelsall Shuttleworth Performance. (KSP, England)
IOMR = International Offshore Multihull Rule (California)

 

TR.NDL.2009 (metr.) catamarans ≤ 20ft = 100 / (0.99 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3000)
TR.NDL.2009 (metr.) multihulls ≥ 20 ft = 100 / (0.99 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3000)
     
TR.NDL.2010 (metr.) Catamarans ≤ 20 ft = 100 / (1.15 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3000)
TR.NDL.2010 (metr.) multihulls ≥ 20 ft = 100 / (1.00 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3250)
     
TR.AUS.2010 (metr.) multihulls ≥ 22 ft = 100 / (1.00 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3250)
TR.THA.2010 (metr.) multihulls ≥ 22 ft = 100 / (1.00 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3250)
Multi2000 (FR)   = 100 / (1.00 * RL ^ 0.3000 * RSA ^ 0.4000 / RW ^ 0.3250)

 

MOCRA (UK) (metr.)   = 100 / (1.74 * RL ^ 0.2814 * RSA ^ 0.3546 / RW ^ 0.3124)
Portsmouth   ref 1 :Starts w/Pacific Multihull Assoc. Calculated rating from measurements (modified)
     

 

RL Rated Length
NDL Rated Length @ 2.0 % x LOA above LWL
AUS/THA Rated Length @ 1.5 % x LOA above LWL
FRA Rated Length @ 50% x FOC above LWL (FOC = Fwd Overhang)
   
MSA Measured Sail Area
RSA Rated Sail Area
   
2010.RSA.Scr.NDL =IF(msascr=0,0,IF(smgscr/sfscr>0.75,0.07*(msascr-rsag),(0.80-smgscr/sfscr)*(msascr-rsag)))
2009.RSA.Scr.NDL =IF(msascr=0,0,IF(smgscr/sfscr>0.75,0.07*(msascr-rsag),(0.82-smgscr/sfscr)*(msascr-rsag)))
   
2010.RSA.NDL =rsam+rsag+rsas+IF(rsas>0,0.16*msascr,rsascr)
2009.RSA.NDL =rsam+rsag+rsas+rsascr
   
2010.CatCorrect.NDL IF(tri=1,1,MAX(1,1/(0.19*rsa^0.4/rw^0.36+0.91)))
   
2010.RSA.AUS No.Screacher & no.Spin
  RSA=RSA.main+RSA.genoa
   
  Screacher & no.Spin
  RSA=rsa.Main+(0.65*rsa.Genoa)+z.85*(0.35*MSA.Screacher)
   
  No.Screacher & Spin
  RSA=rsa.Main+(0.70*rsa.Genoa)+z.85*(0.30*MSA.Spinnaker)
   
  Screacher & Spin
  RSA=rsa.Main+(0.65*rsa.Genoa)
  +z.85*((0.30*MSA.Spinnaker)+(0.50*(MSA.Screacher))

Ref: Texel.NDL.Link , ISAF SCHRS.Link, Texel.AUS.Link, Multi2000.English Link, Portsmouth US Sailing Offshore.Link