The strait is on average 30 km wide and centered at 20°09′N 110°16′E / 20.150°N 110.267°E / 20.150; 110.267 with a maximum water depth of approximately 120 m. The strait is susceptible to closure during strong typhoon activity.
Whales and dugongs were once common in the strait.
The strait was crossed by the People's Liberation Army forces in the spring of 1950 (see Landing Operation on Hainan Island).
The Guangdong–Hainan Ferry (part of the Guangdong–Hainan Railway) carries rail cars and automotive vehicles across the strait.
A 140 billion RMB ($21 billion USD) bridge across the strait is planned to begin construction in 2012. The bridge is currently designed to have levels for both trains and cars, and is expected to be 26.3 km (16.3 mi) long.