The animal, measuring just over one metre, was first spotted on April 11 at a beach in Song Cau Ward. Locals pushed it back out to sea at least three times, moving it hundreds of metres offshore, but it continued to drift back.
The dolphin remains in a fragile condition and has been moved to waters about 50 metres from shore. Authorities are monitoring the situation and preparing to follow local burial customs if it dies.
Earlier, on April 9, a 10 metre whale weighing about two tonnes was found dead after washing ashore at Vinh Hoa Beach in the same area and was buried in line with coastal traditions.
Local fishermen regard such strandings as a sign of good fortune for upcoming fishing trips.