Deck 2014: General Navigation

1. A receive a strong return at about 200 fathoms (366 meters) during the day, and one nearer the surface at night
2. B receive a first return near the surface during the day, and a strong return at about 200 fathoms (366 meters) at night
3. C receive false echoes at a constant depth day and night
4. D have to recalibrate every couple of days due to inaccurate readings

Tip: press A-D to answer