Party in the air

Recent discussions about foil-borne dinghy development have prompted a flood of technical correspondence. David Lugg and Alan Smith were responsible for the airborne International 14 that decorated March 2002's cover. Here they explain the positives - and the pitfalls - of their work to date

The amalgamation of the Australian 14-foot skiff and the International 14 class in 1997 saw the adoption of new rules for the combined I-14 class. The Australian rules had previously restricted increases in centreplate or rudder thickness below the waterline, effectively preventing any extension of their surfaces from providing vertical lift. This rule was abolished in the amalgamation which overnight opened the way for foil-assisted designs. I-14 hydrofoil developments are now proving to be as significant as the step taken from displacement to planing hull forms in the 1950s.

In first electing to attempt a foil configuration that would lift our new hull clear of the water a number of hydrofoil geometries were considered.............

Above: The image is far from perfect - but the dramatic consequence of a sudden imbalance when foil-borne at speed can be clearly seen.

To read this article in full, please go to the MAY 2002 issue of Seahorse International Sailing. You can subscribe via our website's secure form.

Alternatively call, fax or email the Seahorse office to order an individual issue