Photo credit http://www.americascup.com/.
Is a 12 Meter yacht really 12 meters (about 40 feet) long? NO! 12 Meters doesn’t refer the length or any other measurement on the yacht. “12 Meter” refers to the class of yacht. 12 Meter class yachts were designed based on a formula. This meant that 12 Meter Class yachts could vary in sail area, length, and other speed production aspects. Above is the mathematical formula by which all 12 Meter yachts are measured.
This formula inputs speed producing factors – length (L), sail area (Sa), freeboard (F), and a girth measurement (2D) – through a simple mathematical formula. In order for a yacht to be a Twelve Meter the results of this formula must not exceed 12 meters. To limit the likelihood that one 12 Meter design would be vastly superior than another and promote fair and competitive racing there are other restrictions on design measurements of 12 Meter racing yachts. Maximum and minimum parameters on mast height, draft, beam and headsail height are applied to 12 Meter racing yachts to ensure that there is not too much diversity among boats.