Submarines weighing less than 150 tonnes are classified as midgets and are used by the Navies to carry out underwater covert operations and surveillance missions.

The Navy has already initiated the process of procuring these vessels and recently issued a Request for Proposal to Indian shipyards including Hindustan Shipyards Limited, ABG and Pipavav shipyards, Defence Ministry sources said.

Initially, Navy is planning to get only five of these vessels but the inductions can be doubled later on.
The induction of these midgets is part of the Navy's efforts to strengthen its operational capabilities after the 26/11 terror strikes in Mumbai last year, sources said.

With capacity of carrying four to six personnel on board, the submarines would have a diving depth of around 400 metres, they added.

The midgets, sources said, will have the capability of carrying out both manned and unmanned operations and will be equipped with a host of weapons including torpedoes.

Due to their faster speed and smaller size, midgets are able to escape the enemy Sound Navigation and Ranging (SONAR) probes making them useful in carrying out covert operations, they said, and help troops to penetrate into hostile territory without getting noticed by enemies.

These submarines, sources said, would be capable of being launched independently or being attached with larger mother submarines.

Midgets can be taken close to far-off enemy areas by attaching them with conventional submarines and can be launched once they are close to the area of operation.

The midgets can also be deployed along the coastal areas to keep a check on the suspicious activities close to the shores.