The Brazilian Navy participated in World War II in the Battle of the Atlantic, from Brazil's entry into the war in 1942 until its end in 1945. Its campaign consisted of defending maritime traffic against German and Italian submarines, in conjunction with the Brazilian Air Force and the United States Armed Forces, with the latter exercising operational command in the South Atlantic. Its main activities included escorting convoys between Rio de Janeiro and Trinidad in the Caribbean, with additional missions such as escorting the Brazilian Expeditionary Force on its way to Europe.
Submarine attacks against the Brazilian merchant navy were the immediate factor in Brazil's entry into the war and threatened the supply of raw materials to the Allies and the provisioning of major coastal cities. The pre-war Brazilian fleet, consisting mostly of remnants of the Fleet of 1910, was unprepared for anti-submarine warfare. Naval strategists were, until then, more concerned with a regional war between surface forces. A naval program outlined in 1932 reactivated, albeit with difficulty, the construction of warships on national soil. During the war, the adaptation of existing ships, the incorporation, through Lend-Lease, of sixteen submarine chasers (the G and J classes) and eight escort destroyers (the Bertioga class), and training on new equipment created a fleet geared towards anti-submarine warfare, with small but modern ships.
Two task forces were organized: the Northeastern Naval Force (FNNE) and the Southern Patrol Group (GPS), operating respectively north and south of Rio de Janeiro, with other resources assigned to the Naval Commands on the coast. Brazilian Marines garrisoned several ports and Trindade Island. With the combined Allied effort, the submarine threat was almost suppressed by the end of 1943. The Brazilian Navy convoyed 3,164 ships, of which 99.01% reached their destinations. Three ships and 486 military personnel were lost in operation. No enemy submarines were directly sunk by the Brazilian Navy; aviation, which it lacked, was the main destroyer of submarines in operations. Brazilian naval participation in hunter-killer missions would only begin in the final stage of the war.
In the post-war period, the Brazilian Navy aligned itself with the United States in the acquisition of ships and joint preparation for anti-submarine warfare, with Soviet submarines replacing German ones in Cold War naval thinking. A divergence on both points would occur a few decades later. The navy's institutional historical narrative on the conflict opposes the view that only focuses on the Brazilian Army and blames political neglect for the state of unpreparedness and improvisation in which the country found itself.
The pre-war Navy
The Brazilian government declared itself neutral after the outbreak of World War II in Europe in September 1939, and declared war on Germany and Italy in August 1942, entering the conflict on the Allied side. At sea, the threat consisted of Axis submarines (German and Italian) sinking Brazilian merchant ships. The Brazilian Navy was unprepared for this threat. Most of the ships were remnants of the Fleet of 1910, used in World War I. Their state of maintenance was very poor and ammunition stocks were small.
Most assets were subordinate to the Fleet, whose flagship was the battleship Minas Geraes. Its sister ship São Paulo, another remnant of 1910, remained in service, as did the cruisers Bahia and Rio Grande do Sul and five destroyers of the Pará class, one of which, the Paraíba, was not seaworthy. There was another destroyer of a more recent class, that is, from the First World War, Maranhão. Minas Geraes had been refitted in 1935–1939, replacing coal with oil. The cruisers, with a displacement of three thousand tons, were only slightly larger than modern destroyers, and their guns were of 120 mm caliber, below the 127 mm standard of U.S. destroyers. The Pará class destroyers were referred to as torpedo boats in some sources.
The high seas force also included the submarine Humaytá and three T class submarines, two tenders, two tankers and four tugboats. The Minesweeping Flotilla had ten ships, and the Directorate of Hydrography and Navigation had three hydrographic vessels and two lighthouse tenders. The training ship was the sailing ship Almirante Saldanha. These assets were concentrated in Rio de Janeiro, then Brazil's federal capital, but there were river flotillas in Ladário, Mato Grosso, and Belém, Pará. A naval base was under construction in Natal, and others were being considered in Recife and Salvador for operations in Northeastern Brazil. The coastline was patrolled with the few available assets, especially between the mouth of the Pará River and Santa Catarina, including the archipelagos of Fernando de Noronha and Trindade and Martim Vaz.
There was no knowledge or equipment for modern anti-submarine tactics. The ships lacked radar and sonar, and crews were not trained in modern damage control techniques, firefighting, sea rescue, and other procedures. The routine training of battleships in the interwar period was limited to occasional gunnery exercises at Ilha Grande, returning to port the same day. Officers who wished to serve longer at sea volunteered for hydrographic service. There were pockets of expertise in the Submarine Flotilla and Naval Aviation, but the latter was disbanded in 1941, along with its Army counterpart, to create the Brazilian Air Force. Until then, it possessed 97 aircraft.
The Corps of Naval Fusiliers (CFN) had a nominal strength of 2,638 men since 1940. It was essentially a guard infantry with typical Army procedures. The regulations stipulated that they should carry out amphibious landing operations, but there was no equipment or specialized training for such. With the opening of courses at the Naval School for marine and supply officers in 1936, officers promoted from the ranks, who were looked down upon by the Navy Corps, were replaced in the CFN.
Order of battle Organization of naval units in 1940Battleship DivisionMinas Geraes and São PauloCruiser DivisionRio Grande do Sul and BahiaDestroyer FlotillaMaranhão, Piauí, Rio Grande do Norte, Sergipe, Santa Catarina and Mato GrossoSubmarine FlotillaHumaytá, Tupy, Tymbira and Tamoyo Auxiliary fleetTenders Belmonte and Ceará, tankers Novais de Abreu and Marajó, tugboats Aníbal de Mendonça, Muniz Freire, Henrique Perdigão and DNOGMinesweeping FlotillaTen shipsDirectorate of Hydrography and Navigation FlotillaThree hydrographic vessels and two lighthouse tendersTraining shipAlmirante SaldanhaAmazon Flotilla (river)Gunboat Amapá and tugboat Mário AlvesMato Grosso Flotilla (river)Monitors Parnaíba, Paraguaçu and Pernambuco, avisos Oiapoque and Voluntários and tanker Potengi
Interwar naval thought Brazilian naval policy in the interwar period lacked a well-defined orientation. General priorities were centered on the regional scenario, especially the rivalry with Argentina, and on surface operations and units. Naval acquisitions were justified on the basis of defending the eight thousand kilometers of coastline and maintaining parity with the Argentine and Chilean fleets. The Naval War School (EGN) studied hypotheses of a South American conflict with interceptions, protection of bases, transport of Army troops, and the maintenance of maritime communication lines to Europe and the United States. Anti-submarine, however, was ignored. As for fleet composition, proponents of battleships competed with advocates of smaller vessels. Wargames in the 1930s already included aviation, amphibious landings, and wars against European powers, but the enemies employed only surface forces.
The period was marked by economic difficulties and profound reforms. Strategic thinking and tactics were modified by the influence of the North American Naval Mission (MNNA) on the Naval War School (EGN) and the Navy General Staff. Low-ranking officers who had trained in the U.S., the so-called "archdukes," proposed updates to naval thinking. The MNNA contract was signed in 1922, abandoned in 1931, and resumed in 1935. American instructors taught at the EGN. The United States Navy supplanted the British Royal Navy as the main influence on the Brazilian Navy.
Naval administration in the Vargas Era
The Presidency of Brazil was held by Getúlio Vargas from 1930 to 1945. From 1937 onward, Vargas headed, with the support of the Armed Forces, the Estado Novo dictatorship. For most of this period, the Ministry of the Navy was headed by Admirals Protógenes Guimarães (1931–1935) and Aristides Guilhem (1935–1945). Guimarães was one of the former tenentist rebels of the 1920s, amnestied by the president in one of his first measures upon taking power. In the Navy, those pardoned were few and their reintegration was not as difficult as in the Army. Guilhem' long tenure ensured some continuity in naval plans, as decision-making was centralized and personalistic, despite the advisory structure of the Navy General Staff and the American naval mission. The president could choose whether or not to implement the planning presented by the military.
The naval force fought the Constitutionalist Revolution of 1932, contributing to Vargas' stay in power, but many officers sympathized with the rebels. Vargas eventually released funds to the Navy as he needed military support, even amid the Great Depression, and due to foreign policy needs, with two wars in neighboring countries: Colombia-Peru (1932–1933) and Bolivia-Paraguay (1932–1935). The project to reactivate Brazilian shipbuilding was compatible with the government's import-substitution industrialization policy. Steel for shipbuilding was imported from the United States, drawing the ministers' interest to the cause of nationalizing the steel industry. The Estado Novo propaganda exploited keel-laying and launching ceremonies, presenting them as affirmations of nationality, modernity, and development.
Two more movements attempted to overthrow Vargas in the 1930s: the Communists, in 1935, and the Integralists, in 1938. The former did not directly involve the Navy, whereas the latter resulted in the imprisonment of many of its officers and enlisted men. In response, Vargas did not reduce the naval program, but restricted the fuel and ammunition available to the Fleet until 1942. A presidential decision would prove controversial within the Navy: the dissolution of the Army and Navy aviations services to create a new military ministry, the Ministry of Aeronautics, which redistributed the bases of political-military support.
1932 naval program At the outbreak of war in 1939, Brazilian shipyards were working on one monitor, six minelayers, and three destroyers. Another monitor of the same origin had entered service in 1937. Six destroyers, ordered by the Brazilian Navy, were under construction in the United Kingdom, and three Italian submarines had already been commissioned a few years earlier. All were part of a naval program instituted in 1932 and revised in subsequent years. Only a small part of the planned program would actually be implemented in the 1930s.
To finance the program, the government approved, on 11 June 1932, annual credits of 40 billion réis over ten years. The objective was a modest naval force, within the country's financial and technical capabilities. There was no strategic or political planning, only a concern to reduce inferiority to the Argentine and Chilean navies. The official diagnosis in the Ministry of the Navy's 1932 report was that the "fleet is agonizing from age and, having lost the habit of voyages–replaced by the parasitic and bureaucratic life of the ports–all traditions are dying".