If you've never been on a diving holiday you have a real treat in store - because diving takes you into an entirely new dimension. It seems obvious to say so, but until you have experienced it, it's hard to imagine the magical underwater world that is suddenly opened up to you - the closest, in my mind, to space exploration.
The good news is that diving can be learnt relatively quickly and inexpensively - and pleasurably, since dive schools (from the most basic to the more sophisticated) exist in many of the more alluring tropical locations. While some may go on complete diving holidays, for many it's just a day or two spent diving as part of a beach holiday in Egypt or Belize.
So what's to see? Fields of coloured coral, extraordinary shapes and colours, ship wrecks and underwater caverns - each of these teeming environments supports a mini-world of its own. Like all natural environments, these eco-cystems are fragile. Diving is also a dangerous sport. But if you enjoy it, it will make your holiday something special.