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The following plots were drawn from the full data base of 777 boats.
Ignoring the few boats over 80' LOA, the distribution of the data shows that low Disp/LWL ratio boats are common over LOA's between 20 and 80. Higher ratios are more common among boats under 40' and drop slightly as the loa increases.
The averages were:
30'-40' LOA, Disp/LWL = 249 (333 boats)
40'-50' LOA, Disp/LWL = 211 (76 boats)
50'-60' LOA, Disp/LWL = 151 (27 boats)
60'-70' LOA, Disp/LWL = 105 (7 boats)
70'-80' LOA, Disp/LWL = 91 (4 boats)
This is expected since the longer and heavier boats are more stable, require less ballast and beam, and end up with lower Disp/LWL ratios.
The increased stability of longer, heavier boats means they can have "finer" lines. This is apparent in the following plot of LOA/BEAM Vs LOA.
For shorter boats, a low LOA/BEAM ratio has the added advantage of more interior volume, at the cost of handling and drag.
The Sail Area/Disp. ratio is fairly flat (ignoring some of the "freaks") for all lengths. This is probably due to the fact that above a certain "power to weight" ratio, any boat will get difficult to control.
Capsize risk, usually below two for cruising boats, is strongly related to LOA. The longer boats are heavier and have less beam, which greatly reduces capsize risk. Its fairly uncommon for a boat longer than 40 feet to have a capsize value greater than two.
The final plot show the relationship between the Comfort factor and LOA. Again, longer boats clearly have an advantage here, assuming that slower pitch and roll response is desirable.
Revised Jan. 27, 1999