Instead of making the race longer - how about splitting up the Cocoa leg or the Tybee leg. If you made the Jupiter leg longer (although I love the Jupiter stop where it is, but if the beach is going to stay rocky then maybe more thought needs to go into changing that checkpoint) that would make cocoa shorter. Split the last leg from Fernandina and stop in St. Simons, which makes a nice short 30 mile parade into Tybee which makes it easy to plan an event or something at the finish.

Just a thought....