Brazil acquired submarines Humaita and Riachuelo from the USA according to the Australia Station Intelligence Summary dated 1 March 1957

An item reported that the Brazilian acquired 2 submarines from the USA which were lent for 5 years. The 1,525 tons displacement and a length of 311 feet were built in 1942 and presumably of the Gato-class. Brazilian crews already undergone some months of training in the USA.(1)

Note

1. Gato-class submarines Humaita (ex-USS Muskallinge) and Riachuelo (ex-USS Paddle), loaned for 5 years under the MDAP after overhaul at the Philadelphia Navy Shipyard was completed in January 1957.

Source

Website Royal Australian Navy, Sea Power Centre.