UPDATE 21 June 2010: This has now been corrected and the updated version can be downloaded from the Technical section of this website.


Please note that there is an error in the latest IRC measurement manual regarding the measurement of ‘y' for counter stern boats.

On page 14 the drawing for counter sterns should be the same as in the IRC Yearbook, as shown HERE (PDF)

We apologise for any confusion caused.

RORC Rating Office & UNCL Centre de Calcul

3 June 2010