Last Tuesday evening Graeme Armstrong presented the Science of Sailing to members. He explained how such terms as sail area to displacement ratio, displacement to length ratio and ballast ratio are calculated and how each affects the boat's performance. He went on to explain terms such as deadweight, lightship weight, displacement, gross tons and net tons. (Did you know that the last two terms refer to how many barrels the ship will hold, not its weight?)

He illustrated the affect that various parameters have on a yacht's performance by comparing a number of common production yachts as well as a Thames barge and Mirabella V, the world's largest yacht.

A lively discussion was held regarding the GZ curve which was particularly interesting after the recent talk on the Fastnet race and RORC's and ISAF's seaworthiness requirements for offshore racing.

A pdf of his full presentation is here.