Flag U (Uniform)
ICS · U code word: Uniform pronounced: YOU-NEE-FORM (or OO-NEE-FORM) Morse: ··−
In short: You are running into danger.
Single-letter meaning (Pub 102)
You are running into danger.
Morse sign
··−
Dot = short sound, dash = long (three times longer). Hear it in the Morse translator.
In plain English
A warning addressed to another ship: your course is leading you into danger (a shoal, a wreck, an obstruction).
Where you will really see it
Sent from a ship, a shore station or a lighthouse to a vessel standing into danger. One of the signals every navigator should recognise without opening the tables.
Keep going
- All signal flags: the search box and the full grid.
- Interactive mast: build your own hoist.
- Single-letter signals cheat sheet A to Z on one page.
The single-letter meanings are quoted 1:1 from Pub 102 International Code of Signals (NGA, public domain); the plain-English explanations are our own. Flag graphics: signal-flag-images (Unlicense).