Portsmouth Formulas

PORTSMOUTH YARDSTICK Table IV CALCULATION OF PORTSMOUTH NUMBERS AND WIND HANDICAPS FROM RATING FORMULAE AND FACTORS
(D-PN) = A + [B(Rating)] (HC) = (f)(D-PN)
			D-PN
	Class		Formulae Constants		Factors (f) for BN Ranges
Class	Type	Rating	A	B	0-1	2-3	4	5-9
Centerboard Classes	I	MR	143.9	-2.758	1.060	1.010	0.970	0.970
	II	MR	96.0	-0.308	1.071	1.008	0.941	0.941
	III	MR	113.4	-1.392	1.023	1.004	0.973	0.973
	IV	MR	213.1	-8.227	1.010	0.978	0.974	0.974
	V	MR	113.1	-1.790	1.026	1.016	0.967	0.967
	VI	MR	117.6	-1.780	1.055	1.026	0.975	0.975
	VII	MR	205.5	-7.940	1.014	1.001	0.935	0.935
	VIII	MR	109.1	-1.160	1.012	1.010	0.990	0.990
	IX	MR	209.8	-9.231	1.009	0.991	0.985	0.985
Multihull Classes		PMR	14.3	58.74	1.070	1.030	1.000	0.950
Keelboat Classes	I	DR	106.4	-0.952	1.017	1.008	0.984	0.984
	II	DR	110.9	-0.602	1.041	1.021	0.944	0.944
	III	DR	141.0	-2.620	1.017	1.008	0.971	0.971
	IV	DR	124.6	-1.014	1.018	0.986	0.980	0.980
	V	DR	105.5	-0.960	1.048	1.016	0.908	0.908
Offshore Classes	I	DR	114.7	-1.183	1.027	1.023	0.960	0.940
		IOR	110.1	-0.861
		MORC	--	--
		PHRF	(See Table VI)
	II	DR	138.1	-2.167	1.008	1.006	0.990	0.985
		IOR	136.1	-2.190
		MORC	116.5	-0.993
		PHRF	(See Table VI)
	III	DR	155.1	-2.615	1.017	1.008	0.980	0.971
		IOR	109.1	-0.977
		MORC	129.1	-1.493
		PHRF	(See Table VI)
	IV	DR	N/A		1.017	1.008	0.992	0.990
	V	DR	N/A		1.007	1.002	0.992	0.990