The fire was discovered at about 3.10 am at the Tan An Village fishing port, according to an initial report from the Quynh Phu Commune Military Command.
Local authorities mobilised 80 rescue personnel and three fire engines to the scene.
Emergency workers also moved nearby fishing boats away from the danger zone to prevent the fire from spreading.
Five fishing boats moored at the harbour basin caught fire at dawn in Quynh Phu Commune (Photo: V. Thanh).
The blaze was brought under control and completely extinguished after more than an hour of efforts.
Ho Van Thanh, chairman of the Quynh Phu Commune People's Committee, said initial assessments showed that three fishing boats had been completely destroyed, while two others suffered extensive damage to their cabins and upper hulls.
No one was injured in the fire, Thanh said.
The scene of the boat fire at Tan An harbour basin, Quynh Phu Commune (Photo: V. Thanh).
Initial estimates put the damage at several billion Vietnamese dong.
Local police are working with relevant agencies to examine the scene and determine the cause of the fire.