Vietnam's best reef by a distance to 219 coral species with over 40% cover, green turtles nesting in numbers on Bay Canh…Vietnam's best reef by a distance to 219 coral species with over 40% cover, green turtles nesting in numbers on Bay Canh, dugongs in the seagrass, and the occasional whale shark. Remoteness and strict protection kept it while the mainland reefs were fished out. Con Dao was the French colonial penal colony, then a South Vietnamese prison, for over a century, and its tiger cages and cemetery are a national memorial. The isolation that made it a prison is the reason its reefs, forest and turtle beaches survived. Anchorage: Sheltered anchorages on the west side; Con Dao is one of very few Vietnamese islands practical for yachts. Hazards: Vietnamese cruising permits are bureaucratic; arrange well ahead. Monsoon Oct-Feb. More