Naval, border guard and maritime search and rescue vessels continued searching waters around Mui Nghe into the morning of August 9, with designated areas assigned to each vessel.
Nguyen Van La, deputy political officer of Squadron 31 under Naval Region 3, said crew aboard naval vessel 629 were continuing to scour the area for the two missing victims.
One of the four, Truong Thi Phuong, 24, was rescued by the vessel at around 2.30 pm on August 8 after drifting at sea for about eight hours.
Phuong said the group had been walking near Mui Nghe shortly after 4 am when a large wave suddenly swept them into the sea. Three women, none of whom could swim, fell into the water before a man jumped in to try to rescue them.
Phuong initially stayed close to the others but was later swept away by the waves. Unable to swim, she floated on her back to keep her face above water.
After about an hour, she came across a makeshift float made from two plastic containers tied together and used it to keep her head above the water until she was rescued.
Another member of the group, a man born in 1996, was rescued by a nearby fishing boat at around 8 am on August 8.
The other two women, both born in 2002, remained missing as of the morning of August 9.
Authorities have deployed teams to search both onshore and at sea, while vessels operating nearby have also been asked to assist.