The waters around the uninhabited Koh Tang island are known as the site of the infamousMayagüez incident of 1975 in which the Khmer Rouge captured a US ship. They also offer world-class diving, unspoilt by crowds. Five hours from the mainland and best visited as part of a live-aboard trip, divers are rewarded with a stunning diversity of corals and rocky reef dives where you're likely to see barracudas, octopus and seahorses. Nearby Koh Prins has two wrecks to dive. If you don't fancy a live-aboard, head to Koh Rong Saloem, much closer to Sihanoukville. Here you'll dive with kingfish, moray eels and a wide variety ofnudibranch. The island is pretty enough to warrant a few nights of post-dive chilling.
Stay at: The sumptuous Lazy Beach (doubles rooms $25 a night) on Koh Rong Saloem for total relaxation or Eco Sea Dive has simple bungalows (double rooms $30 a night; +855 12 606646).
Getting there: Several tour operators based in Sihanoukville offer overnight trips. Try the friendly Dive Shop which has a stunning new live-aboard boat or the long established Dive Cambodia (Full day trip with two dives costs about US$85 (GBP41 or Euro58).
