| ATE | Took in from undersea terrain (3) |
| EASTERSUNDAY | When Jesus returned from undersea stay, mysteriously (6,6) |
| BARBEDWIRE | It's there to stop progress, apart from undersea cable (6,4) |
| SUB | Undersea vessel, for short (3) |
| EEL | Undersea shocker |
| FREEFORALL | Undersea eco-system examination in Florida results in big argument (4-3-3) |
| ELLIE | What is the name of the girl who joins Tom in the undersea world in The Water-Babies ?(5) |
| TSUNAMIS | Potential three times higher waves from a massive undersea rupture in July 2025, as prophesied. (8) |
| SUBPLOT | Secondary theme I take from leader of undersea craft (7) |
| SONAR | Device used in undersea detection |
| REEFS | Places abundant in undersea life |
| KELP | Algae in an undersea "forest" |
| REEF | Undersea mass formed from the remains of coral |
| UBOAT | Its first letter means "undersea" in German |
| SUBSUMED | Took over undersea vessel, American, coming up on the sea |
| ABERDEEN | In convulsions, undersea began lower (8,5) |
| ANGUS | In convulsions, undersea began lower (8,5) |
| SUPERB | By going in undersea vessel you can see what's brilliant |
| INNERSPACE | Panic seen at sea about start of rumble in undersea region (5,5) |
| TARLTON | NZ diver, undersea explorer and marine conservationist who opened his Underwater World in 1985 (7) |
