Water hyacinth 15-20 cm thick but also plastic waste had piled up along the popular beach on a 20-km stretch, and threatened to affect tourism during the peak summer travel season.
Cao Thanh Qua, 60, said he swims in Bai Truoc every day, and while there is always water hyacinth washing ashore during the rainy season, he has never seen so much.
"The huge amount of water hyacinth and garbage made the beach ugly and dirty."
Local authorities said ocean currents and the monsoon carry the plants and dump them ashore.
Every day workers collect 15-20 tons of garbage.
The authorities have 30 workers, cranes and excavators on the job in Bai Truoc.
Located in the southwest of Vung Tau, Bai Truoc is located between Big Mountain and Small Mountain and is always crowded during weekends and national holidays.