Eleven horizontal stripes, red and white, with a square white canton covering the upper 5 stripes. On the canton, the club badge, two crossed oars with a soccer ball in the upper angle and the initials CCN in the right, left, and lower angles. From the club statute, article 3, at nauticonet. The flag is also shown on the club logo.
From article 9 of the club statute, at sportnet.com.br, seven horizontal stripes, four black and three red; on a square black canton the golden-yellow lion from the club badge, supporting in his forepaws a gold shield with the club monogram (SCR) in black. In the lower right corner of the canton (if I understand the Portuguese correctly) is the founding date of the club (1905) in golden-yellow letters.