DISP / LENGTH RATIO = disp/2240/(.01*lwl^3) Probably the most used and best understood boat evaluation factor. Low numbers (resulting from light weight and long waterlines ) are associated with high performance and quick response
SAIL AREA / DISP RATIO = sail area/(disp/64)^.666 This is a ratio of power to weight, calculated using a 100% jib. We want a cruiser with enough power to sail well but not so much sail that the crew is fatigued by constant sail changes or worried about having a fragile oversize rig.
BALLAST RATIO = weight of ballast / displacement
CAPSIZE RISK = beam/(disp/.9*64)^.333 A seaworthiness factor derived from the USYRU analysis of the 1979 FASTNET Race, funded by the Society of Navel Architects and Marine Engineers. The formula penalizes wide boats for their high inverted stability and light weight boats because of their violent response to large waves
ROLL PERIOD = Time in seconds to complete one cycle. The roll period can be measured by starting the boat rolling slightly (at the dock) and averaging the time for several cycles.
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