A group of ninth graders, all aged around 15, visited a public beach in Phu Loc District on Sunday afternoon.
While they were swimming, Nguyen Huynh Phuc Thinh and Nguyen Van Hien were dragged away by strong waves.
Their friends sought help, and 10 border guard officers and several local fishermen began to look for them.
After around half an hour they found the body of Hien around 20 m from shore.
Lieutenant colonel Ho Xuan Trinh of the Phu Loc border patrol unit said the search for the other boy continued on Sunday night and he was found on Monday morning.
The beach has had strong waves following a tropical depression that ravaged the central region last week.