Ross's subsequent success at sailmaking came during the exploding yachting boom during the early 1960s when, coincidentally, synthetic materials were first available for the crafting of sails.
Ross's work in Dacron gave his staff a medium that held its shape, allowing for the application of aerodynamic theory to sailing.
A material holding shape also allowed for relative mass production, especially when compared to the older, individual sailmaking techniques using Egyptian cotton.
By the mid-1960s, Hard Sails was using a new device – the computer – to accelerate the design process, laying the foundations for Gentry's work between 1969 and 1971.
Torrey designed his first sails via slide rule, plotting curves while riding to his day job on the Long Island Railroad.
It was purchased by competitive sailor William Cox, raised on his Lightning class sailboat, and was the key to winning the World Championship the next year at Buffalo, New York.
Relying on parachute research, Hard Sails created a crosscut spherical chute and dominated the spinnaker market.
Torrey's slide rule mapped these forces, and resulted in the standard-design of radial head spinnakers commanding the market until the early 1990s.
The goal was to produce a “a boat with a large, comfortable, cockpit that could accommodate a gaggle of kids or non-sailors as a good teaching machine.
a fairly flat hull and planned for a jib, not a genoa.”[3] The SONAR class expanded from the Larchmont Yacht Club's Fleet No.