Jeff Grennan has been working on the design of his templates for years. Over the last year we've been working with him to add a high performance foil in order to increase the flow and speed of his fins.
Jeff's idea was to pair a narrow base in order to decrease drag while adding lots or rake in order to retain control down the line and through turns. And boy was he right; his template has become a favorite in the San Diego glider scene and is used by the likes of Skip Frye and Bob Mitsven as well a tons of others.
The Grennan fins are part of our Apex Series lineup. Apex fins are made with precision foiled G10 fiberglass; G10 is made by compressing layers of fiberglass and epoxy resin and baking it an autoclave to have the maximum strength of any fiberglass available.