Vessel Type: Fast Attack Missile Boat.
Names & Pennant Numbers with commission dates:
Displacement: 245 tons full load.
Main Machinery: 3 diesel engines with 10,800 hp sustained and 3 shafts.
Maximum Speed: 37 knots.
Maximum Range: 800 at 25 knots.
Radar: Fire Control; Targeting radar (NATO: Square Tie) in I-band for the P-15M AShMs.
Weapons: Four P-15M (SS-N-2B) AShMs with active radar or infra-red homing with a range of 25n miles; 46km.
Four 30mm guns with 85º elevation & 500 rounds a minute to 2.7n miles; 5km.
Comments: The Osa-II Class missile boats formed the 25th Missile Vessel (K25) Squadron, also known as the Killers, based at Vizag. Osa is the Russian word for Wasp. All eight missile boats have been decommissioned from service.
The Prabal lies on static display at Mumbai's entertainment park, Esselworld and the Chatak is stationed off Marine Drive in Kochi. Admiral Arun Prakash served as the second Commanding Officer of the Chatak from 19 February 1978 to 27 December 1978 and was the chief guest at her decommissioning ceremony in May 2003. Lieutenant Commander S.C. Ghildyal (Retd.) had the privilege of being the Commissioning Commanding Officer of the Chatak, which served for 26 years in the Indian Navy.
The Chapal and the Chamak were the last pair of Osa-II missile boats to be decommissioned on 05 May 2005 at Vizag, after having served for more than 29 years. Commander Harish Behl and Lieutenant Chris J Koshy served as the last Commanding Officers of the Chapal and the Chamak. Rear Admiral Raman Prem Suthan was the chief guest at the decommissioning ceremony of these two vessels. Both vessels saw active participation during the 2004 Navy Day Celebrations, with the Chapal having fired a live missile on 04 December 2004.