Identifying marks on nautical charts

The object at sea and chart symbol are different representations. A buoy has actual form, colour and dimensions; a chart uses symbols, text, conventions and scale. Assigned position is another attribute. IHO S-4 specifies a small positional circle at the buoy symbol’s base, while the stylised body can slope. Its graphic tip is neither part of the buoy’s physical hull nor a waypoint for close passage. The illustration is an original attribute-reading example, not a reproduced chart, and provides no geographic coordinates or depth information.

Ask first about physical nature: floating, fixed or electronic information. Then family and form: lateral, cardinal, ball, cone or another presentation. Then individual name or number, body colour, topmark and light. Fields can be abbreviated or not all shown at the selected scale. A small symbol does not authorise filling unknown attributes with common values. The fictional record separates words to show that familiar shape supplies only part of identity. An actual position and the conventions of its publication remain necessary before drawing spatial conclusions.