Well, the way to build fleets is to work with your local sailors. Last year, we took four Youth Teams to the Hobie Cat National Youth event in Lake Huntington, CA. Like all sailing, only a small percent of the sailors that take classes at Sail Sand Point, in Seattle, move on to racing. While we have six H-16's and next year, twelve Waves in our program, just a few sailors move on to racing. Still working on ways to improve the numbers. Hobie 101, Wed night racing, and increasing Hobie Cat Div 4 events to include Points Regattas and Fun events help.
No magic solution, just work with what you have, and increase the number of volunteers working on the problem.
May not results in Olympic sailors, which is a huge commitment, but will increase the number of racers. BTW, Seattle does have a long list of past Olympic Sailors, and one of our SSP Youth was on the Red Bull Youth America's Cup Team.