Prerequisites
- Distance in nautical miles (nm)
- Realistic speed in knots (kn)
- Departure time (local)
Step 1: Distance
From chart, plotter or log. Coastal: sum waypoints.
Step 2: ETA calculator
Open ETA calculator. Enter nm, kn and departure.
Step 3: Interpret
The app gives passage time and ETA. Allow margin for current, wind and harbour manoeuvres.
Step 4: Align with tides
For harbour entry check Tides and optionally WorldTides key.
Read next: Blog: ETA at sea · ETA feature