Rebellion spread like wildfire through the fleet anchored in Rio de Janeiro. On a number of ships there was sabotage, shots fired and crewmen falling into the water, though no casualties are known from this. However, there were several prisoners taken and wounded near the Arsenal of the Navy and the Ministry's building when disembarking sailors of the Minas Gerais aircraft carrier tried to head to the Metalworkers' Union building and were fired at by officers and marines from the Ministry's building. Two sailors managed to swim away, get to shore elsewhere and walk to the mutineers' building. No pictures of any of this, so look at the ships.

Disgruntled officers were just as engaged in the struggle as the sailors, and placed severe pressure on the minister. In the afternoon the Riachuelo marine battalion was called to the scene and a platoon received tear gas for a second offensive. This was called off by the President as he wanted to negotiate. Admiral Sinay was photographed in tears leaving the scene, announcing he'd resign.