(updated 20 June, 2000)
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 |
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.
