At around 2 p.m. Nguyen Hoa of the Saigon River Tour Co was taking five Australians on a tour between Districts 1 and Cu Chi in his motorboat.
When they reached the Saigon Bridge in Binh Thanh District, he heard people fishing on the riverbank call out to him, asking him to help a drowning woman nearby.
Hoa saw the woman, who seemed to be in her 50s, struggling in the water and quickly reached her.
Two of the tourists on board, a woman and a man, quickly put on life jackets and jumped into the water and rescued her.
The entire episode took around two minutes.
The woman was handed over to the police, whose preliminary investigation found that she was trying to kill herself.