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All questions
Navigation & chartwork

A route crosses an unfamiliar symbol in apparently deep-coloured water. What should you do before relying on the route?

Short answer

Resolve the symbol and qualifiers from the chart key or applicable current reference, then reassess the route

Symbols and abbreviations carry defined meanings and may be qualified by notes, depth, danger or chart context. Colour helps organise the display but does not override the exact symbol. Resolve the governing chart evidence first, then apply tide, draught, margin and route choice. Revise this in Read Depths, Symbols, and Notes.

Sources and scope

Reviewed by Richard Moore on . This answer is scoped to united kingdom and general recreational seamanship; check the current chart, publication, local rules and official operational guidance before acting afloat.

Quick check

A route crosses an unfamiliar symbol in apparently deep-coloured water. What should you do before relying on the route?