Hon Mun Island

Hon Mun (Black Island) is the centrepiece of the Nha Trang Bay Marine Protected Area and the destination for the bay's best snorkelling and diving. The protected waters around the island support an extraordinary density of marine life: over 2,000 coral species and 1,500 fish and invertebrate species have been recorded, including sea turtles, moray eels, and lionfish. Visibility in the dry season regularly reaches 15–20 metres. Most day-trip island-hopping boats include Hon Mun as a snorkelling stop; dedicated dive boats from Nha Trang's several dive centres offer multi-dive days here.

Marine park entry fee approximately 20,000–30,000 VND. Snorkel gear hire on the boat ~50,000 VND. Boats run most reliably from January to August; from September to December rough seas often cancel trips. See March and June for what the sea is like in a good month, or my Nha Trang travel guide for the rest of the bay. Avoid visiting on Vietnamese public holidays when the bay is crowded. For diving, several PADI-certified dive centres in Nha Trang offer fun dives and courses with Hon Mun as the primary site.