Teaching Chart Details: A Navigator’s Checklist
Chart Details are important to a navigator. A basic understanding of these key items is crucial for the ability to read a chart. How many do you know? Which ones are unfamiliar to you?

I’m teaching a couple two-hour courses on charts this month, so I’m sharing with you my list of items to cover with my students. If there’s anything I forgot – please comment below. I strive to learn more, provide more, and better my own knowledge daily.
Chart Details
- Title block
- Datum and soundings
- Scale
- Symbols
- Notes on sides
- Latitude
- Longitude
- Equator
- Zones of Convergence
- Cardinal Directions
- Prime Meridian Greenwich, England
- Antimeridian IDL International Date Line zig zags.
- Large scale = (detailed) small area, small scale = (broad) large area
- Chart scale is the ratio of the distance on a chart to the distance on land or water.
- A scale of 1:8 000 means that the chart is one eight-thousandths of the size of the area it represents: Objects shown as a centimeter apart are physically 8,000 centimeters (80 meters) apart.
- A coastal chart usually has a scale of between 1:50 000 to 1:150 000.
- The scale of a harbor chart is typically 1:10 000 or 1:20 000.
- Hours minutes seconds
- Degrees minutes decimals
- In Geometry use X then Y – along the corridor, then up the stairs; here use opposite; state latitude (N/S) first, then longitude (E/W)
- Notice to Mariners
- Contour lines
- Depth
- Chart No. 1
- True North, Magnetic North, Compass North, difference between them
- Parallels of Latitude
- Meridians of Longitude
- Degrees North of Equator, South of Equator
- Degrees East of Prime Meridian, West of Prime Meridian

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