A troublesome boy gets other children into danger while skin diving, but learns his lesson after a near-fatal accident.
| Actor | Role |
|---|---|
 Anthony BateLieutenant Commander Jim Matthews | Lieutenant Commander Jim Matthews |
| EElizabeth BradleyMrs Haddock | Mrs Haddock |
 Susan GeorgeSusan Haddock | Susan Haddock |
| MMichael WenninkSpike Haddock | Spike Haddock |
| SStephen CraigDerek Matthews | Derek Matthews |
| VVanessa PageVanessa | Vanessa |
| PPenelope WansburyPenny | Penny |
| AAdrian Ellyl-SolerVic | Vic |
| PPatrick CrockfordDusty | Dusty |