Uniform Flag

Uniform, letter U of the International Code of Signals, is a warning: “You are running into danger.” The flag is quartered red and white, red at the upper hoist and lower fly. A vessel or shore station hoists it singly to warn another ship that its present course leads into shoal water, an obstruction, or other hazard. The urgent, unambiguous meaning makes Uniform one of the Code’s most important safety signals.