Interactive signal mast
Type a code (letters and figures, up to 6 characters) or click flags from the library: the signal assembles on the mast in reading order, top to bottom. You can share a ready hoist with a link (the address with ?code=).
Letters A to Z and figures 0 to 9 allowed, up to 6 flags.
The mast is empty. Type a code or click a flag in the library.
Flag library
A click adds the flag to the mast. Right or middle click opens the flag page with its meaning.
A 
B 
C 
D 
E 
F 
G 
H 
I 
J 
K 
L 
M 
N 
O 
P 
Q 
R 
S 
T 
U 
V 
W 
X 
Y 
Z 
0 
1 
2 
3 
4 
5 
6 
7 
8 
9 How flags on a mast are read
A signal reads from the top down; one halyard is one group. The receiver acknowledges with the answering pennant: at the dip when they see the signal, close up when they have understood it. A repeated flag in a group is replaced by a substitute, because a ship carries only one set of flags.
Substitutes and the answering pennant will join the mast in a later version; for now you can build groups from letters and figures.