Observe and identify
Developing level, about 2 min. IALA worldwide marks.
The situation
A navigation light lies ahead. Start playback and watch at least one complete cycle. Its period is an illustrative charted example; identify the combination of colour and rhythm.
Which mark matches the light you observe?
- Safe-water mark
- Port-hand mark · Region A
- Starboard-hand mark · Region A
Answers and explanations
Lookout: Vertical red and white stripes and one red ball. White lights may be isophase, occulting, long flashing or Morse A.
The sound answer
Safe-water mark
Red and white vertical stripes with a red sphere. White isophase, occulting, long-flashing every ten seconds, or Morse A. Indicates navigable water around the mark, commonly at a fairway or landfall.
Why the other options fall short
Port-hand mark · Region A
Red can-shaped lateral mark. In the conventional direction of buoyage, leave it to port. In the opposite direction, leave it to starboard. Read the charted buoyage direction rather than assuming every passage is inward. Here the observed cue identifies safe-water mark. Red and white vertical stripes with a red sphere. White isophase, occulting, long-flashing every ten seconds, or Morse A. Indicates navigable water around the mark, commonly at a fairway or landfall.
Starboard-hand mark · Region A
Green conical lateral mark. In the conventional direction of buoyage, leave it to starboard; travelling against that direction reverses the side of your vessel on which you leave it. Here the observed cue identifies safe-water mark. Red and white vertical stripes with a red sphere. White isophase, occulting, long-flashing every ten seconds, or Morse A. Indicates navigable water around the mark, commonly at a fairway or landfall.
Safe water marks
Red and white vertical stripes with a red sphere. White isophase, occulting, long-flashing every ten seconds, or Morse A. Indicates navigable water around the mark, commonly at a fairway or landfall.