The club competes in Campeonato Nacional de Clubes em Natação (National Club Championship in Swimming) and has achieved multiple trophies both in the men and women departments.
[3] The swimming section is part of the club heritage since its foundation, their first victory was the 'Taça Leixões' in 1908, and then the participation for the first time in the championship of Portugal occurred in 1919.
Names of famous athletes like Abel Guimarães, Adriano Antunes, Alexandrina Pinto, Alíria Silva, António Antunes, António Brenha, António Maria Pereira, Aristides Silva, Edgar Santos, Joaquim Lagoa, and so many others contributed for the club early success.
The section is one of the most decorated in Portuguese competitions, holding the record for most domestic league titles in the former absolut format (held from 1978 to 1986) and also in the women's department and the Portuguese cup (performance variant).
[4][5][6] In the olympics several athletes from the club stood out like Paulo Frischknecht (Montreal '76), Mabílio Albuquerque, Rui Borges and Sergio Esteves (Seoul '88), Joana Soutinho and Miguel Machado (Atlanta '96), Paulo Trindade (Seoul '88, Barcelona '92 and Atlanta '96), Mário Carvalho (Sydney '2000), Luís Monteiro (Athens '2004) and Sara Oliveira (Beijing '2008 and London '2012).