Navigation General · Electronic Nav — Limitations
A prudent watch officer treats ECDIS/GPS as:
- AInfallible and sufficient alone
- BA replacement for keeping a lookout
- COnly a decoration
- DOne input to be cross-checked against radar, visual bearings, and soundings✓ Correct
Explanation
Electronic systems fail, lose signal, or display wrong/old data. Good practice cross-checks the electronic position with independent means (radar ranges, visual bearings, echo sounder) and never relies on a single system or neglects the lookout.
Authority: SOLAS V; STCW watchkeeping
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