| Clue | Source | Date |
|---|---|---|
| Method of finding the depth of water (4-8) | ||
| In-depth method of placing enough on disc (4-8) | ||
| Method of measuring ocean depth | Premier Sunday | 19 Feb 2023 |
| In agreement with keeping sensible assessment of profundity? | The Telegraph Toughie | 26 Apr 2019 |