Observe and identify
Developing level, about 3 min. Chart reading.
The situation
Plan this fictional approach before starting the passage. The western route passes a wreck and a 0.6 m bank; the eastern route has 4.2 m charted depth and a leading line. Water level is +1.4 m, draught 1.8 m, and the stated clearance margin is 0.5 m.
Which route meets the supplied depth and hazard constraints?
- Use the eastern approach and the leading line
- Use the western bank because the wreck glyph is small
- Head straight for the lights without checking depths
Answers and explanations
Lookout: Check the danger, depth, water level and leading line together.
The sound answer
Use the eastern approach and the leading line
The east has 5.6 m actual depth at the stated water level and meets the draught and margin requirement. The west bank leaves only 0.2 m under the keel and the wreck requires additional clearance.
Why the other options fall short
Use the western bank because the wreck glyph is small
Printed glyph size does not establish hazard extent. The western bank also fails the stated clearance margin.
Head straight for the lights without checking depths
A light or leading line must be read with the charted hazards and depths. It is not an independent guarantee for your vessel.
Chart 1 · approach planning
Charted depths, water level, draught, hazard information and routeing cues work together. The chart here is fictional and its numbers are authored training facts.