Signals & flags study overview

Read common International Code flags and understand their limits.

Practise observation and judgement using sailing scenarios. Interactive questions and your device-local progress load when JavaScript is available.

Study points

• India is yellow with a central black disc and means “I am altering my course to port.”
• Oscar is the red-and-yellow swallowtail flag and means “Man overboard.” Treat the signal as urgent.
• Alfa is divided white and blue vertically and indicates a diver down; other vessels should keep well clear at slow speed.
• Quebec is a health/pratique request when used alone; its nickname “quarantine flag” is not its standalone Code meaning.
• November means “No” or “negative” when hoisted alone; bridge signals may use separate local conventions.
• Juliett warns that the vessel is on fire with dangerous cargo on board or that dangerous cargo is leaking, and tells other vessels to keep well clear. Bravo covers taking in, discharging or carrying dangerous goods without that emergency warning; Victor is a general assistance request and Delta warns of manoeuvring difficulty.
• Hotel is white and red in two vertical halves and means a pilot is on board. Golf instead means a pilot is required, with a separate fishing-related meaning.
• Victor means assistance required. Whiskey means medical assistance; Oscar means man overboard; Uniform means standing into danger.

Educational revision only. Check current official rules, charts and publications before navigating.