INT 1 · H 46
Tidal-stream diamond
Tides & currentsCore
A lettered magenta diamond links a chart position to a tidal-stream table.
What it means
The letter inside the diamond identifies a row in the chart's tidal-stream table, which gives direction and rate before and after high water at a reference port.
Why it matters
The diamond itself does not show the current. Use the correct reference port, time zone, and spring–neap interpolation.