| Answer | Crossword Clue |
|---|---|
| DIVINGBELL | Underwater research vessel |
| SEALAB | Underwater research site |
| SUB | Underwater vessel |
| UBOAT | Underwater vessel |
| DIVINGBELL | Underwater search vessel |
| SUB | Underwater vessel, briefly |
| SUB | Underwater vessel, for short |
| DIVINGBELL | Vessel for underwater work |
| hydronaut | a person trained to work in an underwater vessel |
| hydronauts | HYDRONAUT, a person trained to work in an underwater vessel |
| sonobuoy | buoy that emits a radio signal on receiving an underwater signal from a vessel |
