Le Van Ben, 58, from Ninh Binh Province, was rescued late on Saturday in waters near Thuong Mai, about 35 nautical miles offshore.
The search operation involved the waterway police, authorities in Co To Special Zone and local fishermen, including the crew of fishing vessel QN-09083-TS.
Ben was taken ashore for health monitoring at Cam Pha General Hospital in Cua Ong Ward. Authorities said his condition had stabilised.
The incident occurred at around 1 am on Saturday when Nguyen Van Tung was operating an unregistered fishing boat carrying three fishermen to waters southwest of Ha Mai Island and Co To Island.
The vessel sank about seven nautical miles offshore after encountering rough seas and strong waves. Tung and two other fishermen managed to cling to flotation devices and were rescued by another fishing boat, while Ben went missing at sea.
Following the incident, Quang Ninh traffic police deployed three rescue boats and 12 officers to coordinate search and rescue efforts with local authorities, fishermen and fishing associations.
