Signal Flags and Codes2021-12-18T20:27:47-05:00

Introduction: Before the advent of radios, flags and pennants were used to communicate at sea. Each letter and number was represented by a colorful flag. The messages could be seen and read across long distances. Certain combinations of two flags had specific meanings, which were the same in many languages, and could be understood by sailors from different nations.

What to Expect: These flags can be used to create codes known only to your class, to be used for communicating daily messages or schedules. Have students look for signal flags in magazines, catalogues, and paintings- they are still found in many places and are used to add color and a nautical touch.


  • International Code of Signals
  • Flag Codes
  • Construction paper or scrap paper
  • Glue
  • Markers or colored pencils


1. Give each student a copy of the International Code of Signals. Have students color in each flag.

2. Have students use construction paper to make large (8½ x 11) colored flags to tape to their desks or decorate the classroom. Use students’ initials, or refer to Flag Codes for messages.

3. Have students make log books by stapling together several pieces of 8½ x 11 unlined paper. Fold paper in half and cover with folded sheets of oak tag or construction paper. Decorate covers with flag initials. Have students keep records of their marine studies activities in their log books.

4. Give each student a copy of the Flag Codes. Read through the phrases together and discuss situations in which each signal might be used.

5. Have students write short stories, using flag signals instead of the phrases (i.e. “FP,” the captain said. “I hope there will not be a BR, or that we have to AB.”) Read stories aloud to class, having teams or individual students raise hands to translate.

6. Divide class into four groups. Have each group make a list of 5 situations that could occur at sea. Exchange lists and race to see which crew can hoist the proper flags first (sample situation: the first mate has fallen from the yard and broken his back – WK. The North is fighting the South – YX).

7. Have students cover school books with plain brown paper and have them spell out the textbook topic (i.e. spelling, math, reading, etc.) using flags.

Evaluation: Write a brief message to students on the board using flags and flag codes. Students may use their keys to decode and answer with appropriate flags or code.

Extensions: Make miniature flags from stiff paper and glue them to magnets. These can be placed on the board for students and teacher to leave messages. Have students make up a set of two-flag codes for school activities, such as music, math, and recess. The students can list each day’s schedule in flags.


Flag Codes


AB Abandon ship as fast as possible
AR Boat is stove
BN I am seriously damaged
BR Man overboard
BZ Am aground
CM Am drifting; want assistance.
CX Can not assist; do the best you can for yourselves
DS Look out; pay attention.
FJ Send lifeboat to save crew.
FP Bad weather is expected.
FS Be very careful when talking with strange ships.
FZ Heavy weather coming; look sharp.
GD Prepare for hurricane.
GJ Thick fog coming on.
GO You are within reach of guns.
HM Ship seriously damaged; wish to transfer passengers.
ID Heave to or I will fire into you.
IN Let us keep together for protection
JQ Have you any mail for me?
KH Remain by the ship.
KX You will be aground at low tide.
NF Dying for want of water.
NH Fire (or leak); want immediate assistance.
NJ Help, I am attacked.
NV Short of provisions. Starving.
OD Enemy is getting closer.
RN Have you a book of Navigation Tables?
RZ Where am I?
SA Are there any men-of-war about?
SH Where are you bound?
SI Where are you from?
TP Am in quarantine.
UF Report me by telegraph to the “Shipping Gazette”.
VB Sickness is contagious.
WK Have you a surgeon?
YF Want assistance; mutiny.
YL Want immediate medical assistance.
YN Want police.
YO Want provisions immediately.
YR Want water immediately.
YV Peace is proclaimed.
YX War is declared.
ZV Passed a wreck; could not help; people still on board.

Copyright 1998-2008 by Sea Education Association, all rights reserved. Compiled and edited by Pat Harcourt & Bill Meyer.

This project was supported, in part, by the National Science Foundation (Proposals # TEI-8652383, TPE-8955214, and ESI-925324), the Henry L. and Grace Doherty Foundation, the Donner Foundation and the Pew Charitable Trusts. Opinions, findings, conclusions or recommendations expressed are those of the authors and not necessarily of the Foundations.

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