The area where the incident happens.
The incident occurred at 4.30 am when Nguyen Thi Chau, 49, and Le Thi Hong Thuy, 51, and a group of women came to the area to collect seaweed.
Chau and Thuy suddenly slid and fell into the water. Other people in the group could not help due to the darkness and strong waves.
Rescue forces were called and found the body of Chau at 9 am. Meanwhile, Thuy remained missing.
Seaweed is a favourite food to local people and have high prices of between VND250,000-300,000 per kilo.
According to local residents, the harvest season of seaweed starts from October to December when clumps of seaweed appear abundantly on the cliffs and coastal coral reefs.
The harvesting work attracts many local women who usually start from early in the morning and end in the late afternoon.