DLR = (27.87 * IRC Displacement) / LWP^3
Where:
a) LWP = LH – BO – SO
b) IRC Displacement is directly related to Boat Weight. Any addition to Boat Weight will be reflected by a relative increase in IRC Displacement.
c) The calculated value of DLR is rounded to the nearest integer value for printing on each boat’s certificate with 0.5 rounding upwards.
IRC Displacement has not been printed on IRC certificates since 2010 and is thus not something directly available to IRC users.
The sole reason that DLR is printed on certificates is to give event organisers who wish to separate out boats into classes by type another means of categorising their fleet.