Introduction

The following boats were selected by using a Fuzzy Logic process on seven basic evaluation factors: Displacement / LWL ratio, Sail Area / Displacement ratio, V maximum / V hull, Capsize Risk factor, Comfort factor, LOA / Beam ratio and Acceleration. Fuzzy Logic allows boats to be scored according to how "close" they are to the optimal value selected for these variables. The trick is in how you select these optimal values.

To reduce my personal bias, I calculated the optimal values by averaging the data from nine well recognized cruising boat designers, Cruising World Magazine, and several European designers. The data was then averaged to generate the optimal values and calculate the standard deviation. Figure 1 contains the average values for the seven fuzzy variables for each designer, calculated from a total of 151 boats.

DESIGNER	S/D	D/L	CF	CR	Vm/Vh	L/B	ACCEL
ALBERG	15.88	378	31.2	1.67	1.08	3.38	.053
ALDEN	16.65	326	42.6	1.57	1.06	3.77	.056
CREALOCK	15.81	341	36.8	1.64	1.06	3.34	.053
BREWER	16.37	261	33.1	1.69	1.07	3.34	.065
HESS	17.47	256	25.9	1.84	1.13	3.19	.048
HOOD	15.09	325	42.7	1.57	1.05	3.65	.050
MASON	16.53	349	41.8	1.62	1.06	3.51	.049
PAINE	16.97	263	32.7	1.73	1.08	3.33	.075
PERRY	16.72	260	36.0	1.69	1.07	3.35	.070
MISC.	17.45	294	36.6	1.66	1.09	3.33	.060

FIG. 1 AVERAGE VALUES (151 BOATS)

An additional Fuzzy variable has been added to the selection criteria, Acceleration. The Acceleration forces that the crew experiences as a boat rolls can promote fatigue through sleep deprivation, which leads to mistakes and accidents. The Acceleration calculation is based on the beam and roll period. The roll period uses an approximation for the Moment of Inertia based on research by SNAME (Society of Naval Architects and Marine Engineers). A 10 degree roll, with the crewmember located 1.5 feet inside the point of maximum beam, is assumed. The following boats were selected using the "somewhat close" fuzzy hedge.

UNDER 30 FEET

MORGAN 30	MORGAN	0.425
ERICSON 29	KING	0.194
CAPE DORY 28	ALBERG	0.120

30 – 40 FEET

ERICSON 39	KING	0.889
SHANNON 37	SCHULZ	0.785
CREALA 40	CREALOCK	0.777
HORIZON 39	BORGE	0.777
DOUGLAS 32	BREWER	0.701
NORDIA 39	VAN DAM	0.575
MORRIS 34	PAINE	0.518
SIROCCO 34 MS	HOLTROP	0.491
ERICSON 39M	KING	0.472
CAPE DORY 36	ALBERG	0.467
ROBINHOOD 36	ALBERG	0.467
ROBERTS 38	ROBERTS	0.453
VANCOUVER 36	HARRIS	0.450
BLUE PETER	DEVLIN	0.444
CHRIS CRAFT APACHE 37	S&S	0.420
CAL 40	LAPWORTH	0.414
LITTLE HARBOR 38	HOOD	0.411
CONTEST 38	ZAAL	0.389
CORBIN 39	CORBIN	0.383
PACIFIC SEACRAFT 31	CREALOCK	0.336
VALIANT 39 CE	PERRY	0.315
PEARSON 40	SHAW	0.310
ENDURANCE 38	IBOLD	0.309
HR 382	RASSY	0.279
PACIFIC SEACRAFT 34	CREALOCK	0.268
CT-38 SLOOP	WARICK	0.257
VALIANT 40	PERRY	0.244
COLOMBIA 34	TRIPP	0.224
EXCALIBUR 36	VAN DE STADT	0.213
IRWIN 38	IRWIN	0.199
FAST PASSAGE 39	GARDEN	0.172
BENFORD 39	BENFORD	0.162
HALLBERG-RASSY 39	FRERS	0.163
NAJAD 390	KARLSSON	0.140
VANCOUVER 38PH	TAYLOR	0.056
TAYANA 37	PERRY	0.015
ALLIED PRINCESS	EDMUNDS	0.009

40 – 50 FEET

SOU'WESTER 43	RHODES-HINCKLEY	1.000
HALLBERG-RASSY 42	FRERS	0.992
PACIFIC SEACRAFT PH 40	CREALOCK	0.975
CAMBRIA 40	WALTERS	0.962
LAFITTE 44	PERRY	0.898
ALDEN 46/50 MK II	ALDEN	0.858
PACIFIC SEACRAFT 40	CREALOCK	0.815
SEQUIN 44	S&S	0.720
CABO RICO 40	PAINE	0.717
TARTAN 42	JACKETT	0.712
HINCKLEY 42	McCURDY & RHODES	0.710
LITTLE HARBOR 42	HOOD	0.710
NAJAD 420	KARLSSON	0.635
CONTEST 42	ZAAL	0.610
ALDEN 48	ALDEN	0.576
VALIANT 42	PERRY	0.539
PACIFIC SEACRAFT 44	CREALOCK	0.526
BLOCK ISLAND 40	TRIPP	0.523
HEDONISTE 44	IBOLD	0.512
BREHERET 45	CHAUVEAU	0.504
OCC IDEAL CRUISING YACHT	OCEAN CRUISING CLUB	0.438
TROUBADOUR 44 CUSTOM	POCOCK	0.438
BRISTOL 45.5	HOOD	0.429
ALDEN 44	ALDEN	0.427
HALLBERG-RASSY 49	RASSY/ENDERLEIN	0.415
ROBINHOOD 40	ALBERG	0.402
CALIBER 47	McCREARY	0.394
HINCKLEY BERMUDA 40	TRIPP	0.374
CAMBRIA 44-46	WALTERS	0.372
TAYANA 42	HARRIS	0.333
IRWIN 42	IRWIN	0.327
JONMERI 48	NYMAN	0.314
FREEDOM 45	PEDRICK	0.262
FREEDOM 45 CC	MULL	0.262
ACAJUTLA 42	BREWER	0.257
MASON 43	MASON	0.247
SS CUSTOM 42	S&S	0.247
CABO RICO 38	CREALOCK	0.244
MASON 44	MASON	0.239
DESIGN NUMBER 37	WHITE	0.229
SHANNON 43	SCHULZ	0.193
TOPPER HERMANSON		0.177
ROYAL PASSPORT 49	PERRY	0.174
TRINTELLA 47	HOLLAND	0.163
WESTERLY 43	DUBOIS	0.147
COLOMBIA 43 MK III	TRIPP	0.133
ISLAND PACKET 44	JOHNSON	0.125
BRISTOL 41.1		0.120
BREWER AHQUABI	BREWER	0.092
BRISTOL 40	HOOD	0.085
WHISPER	TANTON	0.080
TAYANA 48	PERRY	0.076
MALO 42	OHLSEN	0.063
ENDEAVOUR 42		0.061
VALIANT 42 RS	PERRY	0.021
PILOTHOUSE CUTTER	DIX	0.021
ROYAL PASSPORT 41	PERRY	0.018

OVER 50 FEET

IRWIN 52	IRWIN	0.716
ROYAL 58 PH KETCH	CONTEMPORARY YACHTS	0.415
LITTLE HARBOR 54	HOOD	0.404
KANTER 51	EMPACHER	0.396
SOU'WESTER 52	HINCKLEY	0.293
S & S CUSTOM 50 PH	S&S	0.280
HALLBERG-RASSY 53	FRERS	0.232
ALDEN 52	ALDEN	0.227
SOU'WESTER 51	RHODES-HINCKLEY	0.146
VALIANT 50	PERRY	0.120

Summary

Take these results with a grain of salt. Not all the boats on this list are great world cruisers, they just share a set of common features that indicate a suitability for offshore use, as defined by a group of recognized experts. If your evaluating a boat for offshore cruising, and its not on this list, it would be prudent to determine why. Look at the factors that are different and make sure the "trade offs" they represent are acceptable. Don’t hesitate to ask the designer for an explanation, and apply that to your personal requirements. For example, a crew of four young men may put more emphasis on performance than an older couple. For the guys, lower disp/lwl ratios, higher sail area/disp ratios, lower comfort factors, and higher capsize risk may be acceptable. An older couple will probably be more interested in a higher disp/lwl ratio, high comfort factors, and low capsize risk.

The complete data base and details about the fuzzy logic process used to select these boats can be downloaded, Download the Data Base, for your use. The file is available as a ZIP or regular XLS.