Skip to main content
IALA
COLREG
COLREG
IALA
Lights
Sounds
GMDSS
Language
EN
ES
CA
DE
FR
IT
PT
NL
EL
HR
PT-BR
Quick sprint
Sign in
1/30
0✓
Which practice should be avoided under Rule 20 — Application (Lights)?
A
Treating daytime fog as if navigation lights are optional.
B
Expecting a masthead light on a sailing vessel.
C
Not recognizing the cylinder day shape.
D
Making short blasts too long (2-3 s) — that is neither short nor prolonged, so it is wrong.