Definition
For each hour of a passage leg, the tidal stream is represented by an arrow drawn in the direction of set with length equal to the rate in nautical miles, carrying three arrowheads by convention. Where a leg spans several hours the vectors are laid end to end from the starting position and the sum used as one resultant. Hours are counted relative to high water at the reference port, not clock hours from departure.
Want to apply this on the water?
Ask Saily out loud for an example, a scenario or a simpler explanation.
Talk to Saily