Authorities in the central city of Da Nang released a seal caught by a local fisherman back into the ocean Monday.
At around 7 a.m. the same day, Nguyen Van Xu, 38, spotted a seal caught in his net while fishing some five kilometer offshore.
The seal is around one meter long and weighs 30 kilograms.
Xu brought the seal onshore and handed over the animal to local sea protection authorities.
His action was highly praised and he may be rewarded, authorities said.
The seal was released to the sea shortly afterwards.
Local authorities said it was the first time that a seal, which usually inhabit colder climates, was spotted in Da Nang.