(Photo: VOV)

Ngo Gia Manh, 20, of Dong Tien commune in Co To district, was the first person to find the sea turtle when he sailed to Dong beach with friends.

The group recorded videos and photos of the encounter and posted on Facebook, drawing public attention. In one of the videos, the turtle weighing about 20kg rose from the surface of water three times, with the longest being about 15 minutes.

Previously, dolphins also appeared in the coastal area of Co To island next to the wharf.

This is the first time that a sea turtle species has been spotted since a 125kg sea turtle was released into the sea 10 years ago.

Co To island district is one of the 16 marine protected areas approved by the Prime Minister due to its rich biodiversity.