Learn nautical signal flags.

The flag reference

• All 40 flags: the 26 letter flags, the 10 numeral pennants, the answering pennant and the three substitute pennants.
• Search by letter, name or meaning, switch between Letters, Numbers and Pennants, and tap a flag for its colours, its Morse and, for the letter flags, its meaning.
• Short plain-language meanings that follow the International Code of Signals.

The flag quiz

• Rounds of 10 questions: name the flag, give the meaning of a flag, or choose the flag for a meaning.
• A running streak during the round, then a results screen that lists the flags you missed.

Spell a word as flags

• Type a word or a short phrase (letters and digits, up to 32 characters) and see it as a flag hoist, with the flag names listed under it.
• A space starts the next hoist, a repeated flag can use a substitute pennant as the Code does, and any character without a flag is listed instead of dropped.
• Turn the hoist into an image and send it from the Android share sheet.

Morse and Semaphore tables

• Morse and Semaphore for every letter and numeral, next to its flag.

Nautical Flags Pro, one optional purchase

• Exam sets: a mixed exam of 20 questions, a timed exam of 20 questions in 5 minutes, and topic exams (danger and warnings, manoeuvring and movement, port and pilot, help and talking).
• A review round that asks again only the flags you missed.
• Progress history: your accuracy for every flag and your past rounds.

No subscription. The flag reference, the 10-question quiz, spelling words as flags and the Morse and Semaphore tables keep working without Pro.

Works offline

Everything except buying or restoring Pro works without a connection. Your answers and rounds stay on your phone. There is no account and no analytics, and you can clear your progress in More. The app uses the network only to reach Google Play and RevenueCat (the Pro price, buying Pro and restoring a purchase), for Google’s occasional rating prompt, and for links or sharing you choose.

A study aid

Nautical Flags is a study and reference aid. It is not for real signalling or navigation. Check the current International Code of Signals and the rules that apply where you sail. The flags are drawn in the app from published descriptions, and the meanings are short summaries written for this app. This app is independent of the organisations that publish the Code.