Sailing between islands with charter guests in Greece during the sunny summer months can work up an appetite—but when the weather's hot, not for heavy food. Aboard Stressbuster, our Atlantic 70 cutter, we often drop anchor at midday for a swim. After cooling off in the clear sea, there's nothing better than to indulge in a favorite Greek afternoon pastime—a light lunch of mezedes (small plates of varied food) with whatever cool beverage you fancy. One of our favorite additions to this summer repast is cool, delicious Greek tzatziki. Made with thick and creamy Greek yogurt, grated cucumber, and a bit of garlic, lemon and fresh dill, it's a perfect addition to the light meal. Served along with a bit of grilled fish, grilled meat, some sliced summer tomatoes, cucumbers, bread, Kalamata olives and a glass of wine, it's a perfect, cooling addition. The Greeks consider this mezede a salad, and actually will eat it as is; most Americans prefer to serve and eat it as either a side (like a relish), or as a dip with either bread, pita or sliced raw veggies. There's nothing better to serve with anything grilled; just dip sizzling pieces in tzatziki before popping in your mouth. It's versatile: You can add ingredients to taste, or even substitute fresh mint for dill for a different flavor entirely. This is so good, it can even stand alone as a cocktail-hour snack. Kali orexi—good appetite!