Pretty simple to me.
Class provides.
1. Class Rules. Whatever they might be they have to be written down.
2. Nationals regatta where all members of the class can come together once a year to race (and drink beer).

Bonuses some not needed for smaller classes.
1. A way to qualify for Worlds.
2. Regional regattas
3. Point systems to win a Region
4. Group buys for items that are not easily obtained individually such as Masts.
5. Youth grants / Ways to get Youth into class /
6. Seminars / Classes / Tuning guides.
7. A website to obtain information

I'm sure I'm missing things.