Dadonghai sits about 3 km south-east of central Sanya, so reaching it means first getting to Sanya. Sanya Phoenix International Airport (SYX), 15 km west of the city, has direct flights from most major Chinese cities and a growing list of international ones — Hong Kong, Seoul, Moscow, Singapore. From the airport, the metered taxi to Dadonghai runs around 80-100 yuan, or take Bus 8 to the centre and change.
The Hainan High Speed Rail loops the island and connects Sanya to Haikou in about 1.5 hours — a scenic ride along the coast. From Sanya railway station, take a local taxi (about 30 yuan) to Dadonghai. From Sanya city centre, public Bus 2 and Bus 8 run to Dadonghai every few minutes for 2 yuan, or take a taxi for about 20 yuan.