| Answer | Crossword Clue |
|---|---|
| GOAHEAD | Kind of signal |
| SONAR | Kind of signal |
| BUSY | Kind of signal |
| TURN | Kind of signal |
| SMOKE | Kind of signal |
| DISTRESS | Kind of signal. |
| GONG | Kind of signal. |
| WINK | Signal of a kind. |
| BEEP | Signal of a kind |
| FLARE | Signal of a kind |
| DIALTONE | "Ready" signal of a kind |
| FLASHERS | Signal lights of a certain kind. |
