The Brazilian Navy currently operates a flotilla of four Tupi-class (modified German Type 209) submarines, which are based at Almirante Castro e Silva, Mocangue Island, near Rio de Janeiro. The first of class was constructed at Germany'sHowaldtswerke-Deutsche Werft (HDW), while the remainder were built at Arsenal de Marinha do Rio de Janeiro (AMRJ).— AMRJ launched a fifth boat, the improved Tupi class Tikuna, on March 9, 2005.— In the near future, Brazil plans to begin constructing a new class of five diesel submarines.[1]— These submarines are to be a further step in the eventual creation of a fleet of nuclear-powered attack boats, which will use the same hull as the new diesel boats. According to Brazilian reports in late May 2004, a special budget of approximately $7.8 million was to be released immediately for the completion of the land-based nuclear reactor prototype RENAP-11 (Reator Naval de Potência de 11 Megawatts), which was expected to become operational in 2005.[2]— The RENAP-11 will then be modified for use in the SNAC-2 nuclear-powered submarine program (which will reportedly require a 48 megawatt PWR reactor).[2,3] As a follow-up to a 2008 defense cooperation agreement, the Brazilian Navy signed detailed contracts in late 2009 with the French naval manufacturer Directorate of Shipbuilding and Services (DCNS). These contracts included technology transfers and construction assistance for four Scorpene-class diesel-electric attack submarines, as well as one nuclear powered vessel. With the exception of the first boat, all submarines will be built entirely in Brazil. The first Scorpene-class vessel is expected to leave the drydock around 2015, while the nuclear submarine's construction is planned to be finished by 2021 and will incorporate the RENAP 11.

The Brazilian Navy is responsible for the protection of some 7,400 km of coastline.— Brasília's submarines are a critical part of this effort.— In addition to attacking the sea lines of communication of the enemy, they can be employed for power projection through the disembarkation of special forces, for intelligence collection, and for laying mines.[4]

Sources:
[1] "The Brazilian Navy - A Naval Force in Evolution," Military Technology, Vol. 29, No. 4 (April 2005), pp. 75-77; in ProQuest Information and Learning Company, http://proquest.umi.com.
[2] "Brazil Accelerates Reactor Work For Nuclear Submarine Program," Sea Power, Vol. 47, No. 7 (July 2004), p. 44; in ProQuest Information and Learning Company, http://proquest.umi.com.
[3] "Programa de Submarinos e Submarinos Nucleares de Ataque(SNA) da Marinha do Brasil," www.infomarmb.hpg.ig.com.br.
[4] Hartmut Manseck, "Submarine Class 209," Naval Forces, Vol. 24, No. 4 (2003), p. 75; in ProQuest Information and Learning Company, http://proquest.umi.com.