Keeping track out of sight of land
- Maintain a running estimated position from the course, the log and the tidal stream between fixes; do not rely on GNSS alone.
- Fix by GNSS cross-checked against the echo sounder, radar ranges, and any lights or marks as the coast comes up.
- Use radar and AIS for collision avoidance and for identifying the coast at night or in poor visibility.
- Keep an independent, non-electronic fallback — a paper chart and a plot — in case the electronics or the power fail.
The discipline offshore is to treat every electronic position as a measurement to be confirmed, not a truth to be followed. A running EP kept alongside the GNSS means that if the GNSS jumps, fails, or is quietly wrong, the discrepancy is obvious rather than fatal. Near the coast the echo sounder becomes a primary safety instrument, independently confirming or contradicting the charted depth beneath the plotted position.
Making a safe landfall
Closing the coast at night
- Identify the landfall light and confirm its characteristic — colour, period, flashes — before committing to close.
- Use a safe depth contour or a clearing bearing to stay off the dangers until the position is certain.
- Cross-check the GNSS position against the light's bearing and the depth.
- Only start the pilotage into harbour once you are sure where you are; if in doubt, stand off and wait for light.
WARNING — Cross-check, never blind-trust A confident but wrong GNSS position is the classic offshore trap. Keep a running EP and confirm the electronic position against depth, radar and any visible mark, especially as you close the land.
TIP — The echo sounder is your independent witness Offshore, the depth under the keel is a fix component the GNSS cannot fake. A sounding that disagrees with the charted depth beneath your plotted position is a warning to stop and check, not to press on.