| Answer | Crossword Clue |
|---|---|
| submarined | SUBMARINE, to travel by submarine |
| submarining | SUBMARINE, to travel by submarine |
| submarine | a submersible vessel / to travel by submarine |
| HST | First U.S. pres. to travel in a submarine |
| periscopes | An apparatus consisting of a tube attached to a set of mirrors or prisms, by which an observer (typically in a submerged submarine or behind a high obstacle) can see things that are otherwise out of sight |
| periscope | An apparatus consisting of a tube attached to a set of mirrors or prisms, by which an observer (typically in a submerged submarine or behind a high obstacle) can see things that are otherwise out of sight |
