You can integrate a dinner trip with a survey of the nighttime street vendors on Avenida Santiago Marino or a trip to the casinos or you can have a great lunch during an island tour. If you like lighter wind, sail in the morning then go out to lunch and tour. If you like higher wind, tour in the morning, have lunch, and be back in time for the afternoon blast. Margarita is an incredibly diverse and beautiful island. Many windsurfers are so focused on sailing that they don't even explore the island.
Several companies offer island tours with English speaking guides.
If you have a sense of adventure you can rent a car and find your own way. This gives you more freedom than a tour and the price is equivalent if you hook up with some friends. A Volkswagen Beetle is the best deal and brings back memories for most folks. Rocky can arrange delivery of a rental car to you. It's best if you plan ahead by one day to ensure availability.