Observe and identify
Developing level, about 2 min. IALA Region A.
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?
- Preferred channel to starboard · Region A
- Preferred channel to port · Region A
- Port-hand mark · Region A
Answers and explanations
Lookout: Can and cylinder mean port; use Region A for the colour; the broad contrasting band identifies a channel division.
The sound answer
Preferred channel to starboard · Region A
A red port-hand form with a broad green band identifies a junction. Following buoyage, leave it to port for the preferred branch to starboard. The chart still determines whether either branch suits your vessel.
Why the other options fall short
Preferred channel to port · Region A
A green starboard-hand form with a broad red band identifies a junction. Following buoyage, leave it to starboard for the preferred branch to port. Its light uses composite group flashing (2+1). Here the observed cue identifies preferred channel to starboard · region a. A red port-hand form with a broad green band identifies a junction. Following buoyage, leave it to port for the preferred branch to starboard. The chart still determines whether either branch suits your vessel.
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 preferred channel to starboard · region a. A red port-hand form with a broad green band identifies a junction. Following buoyage, leave it to port for the preferred branch to starboard. The chart still determines whether either branch suits your vessel.
Modified lateral marks · Region A
A red port-hand form with a broad green band identifies a junction. Following buoyage, leave it to port for the preferred branch to starboard. The chart still determines whether either branch suits your vessel.