🔍 Key Concepts
• Dead Reckoning (DR) position vs. time – how to plot and read where you are at a specific time on the track line
• Charted areas and symbols – differences between restricted areas, regulated areas, traffic separation schemes, and pipelines
• Boundaries and labels on the chart – look at when your DR track crosses a clearly marked line or symbol
💭 Think About
• On your DR track, where is your vessel located at about 1817, and what specific line, symbol, or boundary does it coincide with at that moment?
• How are restricted areas, regulated areas, traffic separation schemes, and pipelines each shown on the chart, and which of those styles of markings lies directly under your DR at 1817?
• Does your DR show you entering, crossing, or leaving a marked area or feature at that time, and how does that relate to the wording of each option (enter, depart, cross)?
✅ Before You Answer
• Confirm the exact DR time marks on your track (e.g., 1810, 1815, 1820) and interpolate where 1817 falls between them.
• Verify the chart symbol and label at the point where your DR is at 1817 (e.g., ‘Restricted Area’, ‘Regulated Area’, TSS lane/zone, pipeline).
• Check whether the DR at 1817 is just inside, outside, or directly on the boundary of that feature to decide if you are entering, departing, or crossing it.