OK, so this is what I was looking for when I got distracted by Robinson Crusoe, The Flashing Blade and Belle & Sébastien (btw welcome tunasters!):

The fact is: When I was five years old, the person I absolutely wanted to be most in the whole world was Marine Boy.

He could swim. Underwater. For ages because he had… OXY-GUM. Oh and his best friends were Neptina the mermaid and Splasher, the dolphin.

One of my earliest, fondest memories of school is swimming around the playground in propellor shoes, chewing oxy-gum and beating up sea monsters with my electric boomerang.