Goa Shipyard Limited (GSL) is an Indian Government owned ship building company located on the West Coast of India at Vasco da Gama, Goa. It was established in 1957, originally by the colonial government of the Portuguese in India as the "Estaleiros Navais de Goa", to build barges to be used in Goa's growing mining industry, which took off after the establishment of India's blockade of Goa in 1955. In the wake of Portugal's defeat and unconditional surrender to India following the 1961 Indian annexation of Goa, it was requisitioned to manufacture warships for the Indian Navy and the Indian Coast Guard. GSL is undergoing a modernisation of its yard to adapt to the latest technology in shipbuilding. To this purpose it is negotiating with well-known shipbuilders for an arrangement to collaborate. To date it has built 167 vessels, including barges, tugs, landing craft, offshore patrol vessels and other vessels for the Indian Navy and Coast Guard and for export to countries like Yemen. A new slipway has been commissioned to take up major repair jobs of ships in the dry dock area. A damage control simulator and two double boom level luffing cranes for heavy lifting have been constructed. Military ships built GSL has built the following ships for military use: Landing craft Mark II L34 – commissioned 28 January 1980 L33 – 1 December 1980 L35 – 11 December 1983 L36 – 18 July 1986 L37 – 18 October 1986 L38 – 10 December 1986 L39 – 25 March 1987 Saryu class offshore patrol vessel INS Saryu (P54) INS Sunayna (P58) SLNS Sayurala (P623) SLNS Sindurala (P624) Vikram class offshore patrol vessel CGS Varad (40) – 19 July 1990 CGS Varaha (41) – 19 July 1990 Samar class offshore patrol vessel CGS Samar (42) – 14 February 1996 CGS Sangram (43) – 29 March 1997 CGS Sarang (44) – 21 June 1999 CGS Sagar (45) – 3 November 2003 Tarantul I class missile corvette INS Vinash (K47) – 20 November 1993 INS Vidyut (K48) – 16 January 1995 INS Prahar (K98) – 1 March 1997 Lost at sea on 22 April 2006 INS Pralaya (K91) – Missile Corvette 18 December 2002 Extra fast patrol vessel CGS Sarojini Naidu (229) – 11 November 2002 CGS Durgabai Deshmukh (230) – 29 April 2003 CGS Kasturba Gandhi (231) – 28 October 2005 CGS Aruna Asaf Ali (232) – 28 January 2006