This article is solely focused on Indian Naval Fleets, as there has been limited information available in public domain around them - How many fleets India has ? Where are they home-ported ? What is the general structure of the fleet when it moves to the open ocean on a mission or on a strategic exercise. Naval fleets do not sit idle in the peace time, on the contrary they are actively engaged on variety of missions throughout the year.
A naval fleet may be absorbing an altogether new platform in the fleet, like Shivalik Class Stealth Frigate, or Akula Class SSN. The arrival of a new type of platform requires development of a new standard-operating-procedures and their implementation through exercises. The capability enhancements brought into the fleet by the new advanced platforms needs to be gauged and validated, so that they can be judiciously employed and exploited to the maximum in the hour of need.
Another case could be development of a a new naval doctrine - due to changes in the threat levels in the area-of-operations; acquisition of a new platform by an adversary, this newly-acquired strength of an adversary needs to be countered. The new naval doctrine needs to be validated through exercises based on scenarios which simulate real-time situations.
Coming back to the Naval Fleets - India has got three major Naval Fleets, namely - Western Naval Fleet, Eastern Naval Fleet and Southern Naval Fleet. Apart from these three major fleets, there is another fleet based in Andaman and Nicobar, known as Far Eastern Naval Fleet under Andaman and Nicobar Joint Service Command. Far Eastern Naval Fleet is still under a development stage, but considering the current geopolitical scenario, it is destined to be the most strategic and active fleets of Indian Navy within a horizon of two to three years.
Indian Naval Bases ( Image Courtesy - Wikipedia )
Western Fleet moves under the flagship of INS Viraat, with a battle group supported by Delhi Class Destroyers, Talwar/Shivalik Class Frigates, Sindhughosh Class Diesel-Electric Submarines, and Aditya/Deepak Class Replenishment Tankers. The major bases of Western Fleet are Bombay and Karwar. INS Vikramaditya is expected to be home-ported at Karwar, along its Carrier Battle Group.
Eastern Fleet currently has INS Jalashwa, Trenton Class LPD, Delhi Class Destroyers, Talwar/Shivalik Class Frigates, Sindhughosh Class Diesel-Electric Submarines, and Aditya/Deepak Class Replenishment Tankers. Along with these platforms, INS Chakra, an Akula Class SSN is also home-ported here. INS Arihant is also expected to be home-ported on a new naval base Rambili under Eastern Naval Command, which is under construction and is being developed as a major base for nuclear-powered submarines. The major base of Eastern Fleet is Vishakhapatnam, which will soon be augmented by the new naval base, INS Rambili.
Southern Fleet has a number of platforms targeted towards coastal defense, naval training, and piracy control, these platforms include INS Tir, INS Kalpeni, INS Sukanya, INS Tarangini, etc. The major base of Southern Fleet is Kochi.