I think you`ll find that most athletes in most sports at the level we`re discussing spend very little time at home, and travel to all the top-level competitions, and compete against the same competitors that they will face in the Olympics many times over before they get to the Olympics.
For these athletes, competing at home is just a formality they have to endure to qualify as the top sailors in their country - In some countries there is no active class at all, and a sailor who wants to compete in the Olympics must qualify through placing well at international events rather than being selected as the best in his own country.
To think that a local sailing program can produce Olympic quality athletes is going to give you a nasty surprise. Aspiring Olympic sailors have to spend most of their time travelling to international events to stay current with what pace they have to maintain to be in with a chance.

Of course, I understand that the local sailing programs are important to get sailors closer to that level, but it`s still a huge jump from being the Tornado national champ to coming 17th at the Olympics.

Cheers
Steve