Myanmar National Airlines has daily flights, and Asian Wing Airways has 3 flights per week, from Yangon. Myanma Airways flights (typically once a week) to Mawlamyine, Dawei, Myeik and Kawthoung may also be available.
Flights may be cancelled with little or no advance notice, due to lack of bookings, the weather, or any number of other unpredictable circumstances. Not much to see from the plane due to air pollution. Skies are clear after rainy season, in Oct-Nov.
Buses are run to/from Myeik and Kawthoung.