| A ship has been communicating effectively on 16 MHz during daylight hours with a shore station at a distance of 3500 miles. Toward late afternoon and evening what effect would be noticed? |
| A) Communications should be maintained with slight improvement in the signal received from the shore station. |
| B) The gray line effect will prevent communications after dark. |
| C) Communications should gradually deteriorate and become impossible on this frequency at night. |
| D) Communications should improve and peak at night. |
