The sea mammals typically weigh roughly one to two tons for each small one and as heavy as 20 tons for each big one, with the creatures spotted swimming between 5 a.m. and 7 a.m. on August 4, reported The Voice of Vietnam (VOV).

Whales are spotted off south-central Vietnamese coast. (Source: Tommy Toan)

Do Thanh Toan, also known as Tommy Toan, a 37-year-old witness, said that the blue whales seemed to be hunting close to the shore.

This comes after Toan found two blue whales in the waters off Hon Trau Island on July 26, an area which is 45 minutes by canoe from De Gi beach.

Blue whales being spotted close to De Gi beach is a rare phenomenon over recent years, particularly as local fishermen consider them to be signs of good luck.

Source: VNA