Observe and identify
Developing level, about 2 min. International COLREGs / IRPCS.
The situation
A vessel ahead is showing a daytime shape. Inspect the shape and its vertical arrangement with the binoculars. The vessel’s name and status are withheld until your answer.
Which operation or status does this daytime signal indicate?
- Constrained by draught
- At anchor
- Sailing vessel using machinery
Answers and explanations
Lookout: A black cylinder may be displayed by a power-driven vessel constrained by her draught. Depth and width severely restrict deviation from her course; the cylinder is not a universal priority ranking.
The sound answer
Constrained by draught
A black cylinder may be displayed by a power-driven vessel constrained by her draught. Depth and width severely restrict deviation from her course; the cylinder is not a universal priority ranking.
Why the other options fall short
At anchor
At anchor uses ball. The displayed signal here indicates constrained by draught. A black cylinder may be displayed by a power-driven vessel constrained by her draught. Depth and width severely restrict deviation from her course; the cylinder is not a universal priority ranking.
Sailing vessel using machinery
Sailing vessel using machinery uses cone-down. The displayed signal here indicates constrained by draught. A black cylinder may be displayed by a power-driven vessel constrained by her draught. Depth and width severely restrict deviation from her course; the cylinder is not a universal priority ranking.
Rule 28 · Day shapes
A black cylinder may be displayed by a power-driven vessel constrained by her draught. Depth and width severely restrict deviation from her course; the cylinder is not a universal priority ranking.