The blaze was reported around 1.30 a.m. on one of the two boats anchored beside each other. The fire quickly spread to the second boat, apparently owing to the strong wind.
Even as naval and dockyard firemen battled the blaze to save the vessels, the boats sustained huge damage and heavy ingress of water.
By around 8 a.m. when the conflagration was controlled, the two boats — both made of fibre-glass — had sunk in the shallow harbour waters.
There were no human casualties in the incident. A Board of Inquiry has been ordered.
Efforts are underway to salvage the two boats — the make and type of which has not been disclosed yet — and after examining them, a decision would be taken whether they are still service-worthy.
An official assured that barring the two boats which were used for security patrols in the high seas, there was no damage to any other defence assets.