ultramarin marine translations
ultramarin.online
nl verhouding zeiloppervlak-waterverplaatsing    
de Segelfläche-Verdrängung-Verhältnis  
en sail area-displacement ratio
Bruce number		 (SADR) nondimensional expression of the relationship between a boat's sail area and its displacement. It is calculated by dividing the nominal sail area (sqft) by the boat's displacement (cft) to the two-thirds power.
The displacement is converted from pounds to cubic feet by dividing displacement by 64, the weight of a cubic foot of seawater.
The standard displacement used by most yacht designers for comparative purposes is the half-load displacement, calculated with the boat equipped for sailing with the crew and half the consumables (provisions, water, fuel, supplies) on board.
The nominal sail area is calculated as the sum of the foretriangle area (one-half the base, or J dimension, multiplied by the height, or I dimension) and the mainsail area (one-half the foot, or E dimension, multiplied by the hoist, or P dimension).
The SADR is termed nondimensional because sail area in square feet is divided by a displacement term that has been converted from cubic to square feet. This mathematical manipulation results in a parameter that again is independent of boat size. Therefore, a 30-footer with a SADR of 20 will have just as powerful a rig as a 60-footer with the same SADR.
Bruce number: the root of the sail area (sqft) divided by the third root of the displacement (pound)
fr rapport surface vélique-déplacement  
es relación area de velamen/desplazamiento  
it rapporto superficie velica/ dislocamento