Union Island is the working gateway to the Southern Grenadines: a dry, hilly island with Clifton Harbour, Chatham Bay, Ashton Lagoon, and fast access to the reefs and turtles of Tobago Cays Marine Park. Tobago Cays itself is the jewel: five tiny cays, a vast protected lagoon, the four-kilometre Horseshoe Reef, and some of Saint Vincent and the Grenadines' signature drift, wreck, and turtle-snorkel experiences.
For divers, Union gives you the logistics, local operators, and easy night dives. For snorkelers and freedivers, the inside of Horseshoe Reef and Baradal's turtle reserve are the headline draw. For non-divers, there are ridge hikes, birding, kitesurfing culture, beach barbecues, and sunset coves. The catch is that this is a remote, weather-sensitive destination where boats, moorings, park rules, and storm recovery all matter. Plan well, travel light but smart, and it rewards you with one of the Caribbean's most memorable mixed-water itineraries.