5 Metre

5 Metre is a development sailing class of French origin.

History
The 5 Metre rule was created in France in 1929 and not a according of the International rule in contrast to other Metre yachts.

The formula
The measurement formula is given in the 2021 International Five Metre Rating Rules:



5.000 \mbox{ metres} = \frac{L + \sqrt[2]{S} - F - \frac{B} {2}} {2} $$

where
 * $$L$$ = length for rating (as defined by rule 3.4)
 * $$S$$ = measured sail area
 * $$F$$ = freeboard in metres (as defined by rule 3.5)
 * $$B$$ = width in metres (as defined by rule 3.6)