There are various levels of work involved in having a ''racing bottom''. I generally fari the bottom on my boats if they haven''t been faired before I bought the boat. Fairing involves taking small waves out of the hull by filling and long boarding the bottom. The applying a barrier coat over the faired bottom. The keel and rudder are also carefully faired.
When I was racing my boat regularly I typically used Baltiplate (although VC seems to have picked up more of the market lately). Baltiplate is good for two years but needs to be cleaned by a diver everyother week in the worst of the summer and before any race. VC has even less antifouling.
A fair and smooth bottom makes a big difference in light air when any reduction in friction is significant and in really heavy air where less friction means less heeling and more surfing.