What does it mean if a vessel is flying a red bravo flag from the mast?

The red bravo flag is an internationally recognized signal indicating that a vessel is transferring fuel or hazardous cargo. This flag serves as a warning to other vessels in the vicinity to exercise caution due to the potential risks associated with such operations. It alerts them that flammable or dangerous materials are being handled, which necessitates increased awareness and safety measures to prevent accidents.

In maritime practice, this flag ensures that other ships and individuals are informed of the ongoing hazardous activity, providing a standard protocol that improves safety on the water. Proper communication using signals like the red bravo flag is critical for maintaining safe navigation and operations in busy maritime environments.