Bowditch describes dead reckoning (DR) as the determination of position by applying course steered and distance run from a known starting point. Which statement best describes a key limitation of DR?

1. A. DR cannot be used in conjunction with electronic navigation systems
2. ✓ DR accuracy degrades over time and must be confirmed by external fixes whenever possibleCorrect
3. C. DR is only valid in open-ocean conditions and cannot be applied in piloting waters
4. D. DR requires celestial observations to establish the initial known position