Whale sharks are spotted on Utila year round, they are deep divers up to thousands of feet and come to the surface to feed. Utila's geological make up is perfect for this. The Northside borders the Cayman trench dropping into the abyss and the fringing reef, inland lagoons and mangrove are host to many different types of snapper and grouper that spawn dureing the FULL MOON and LAST QUARTER MOON. Check out the lunar calendar for the best dates to vist Utila and see whale sharks!! http://lunaf.com/english/moon-phases/lunar-calendar-2011/http://lunaf.com/english/moon-phases/lunar-calendar-2011/