People often ask me about my favourite kind of diving, and seem surprised when I tell them that the UK is far and away the most fascinating destination.
     British diving has opened my eyes. It has enabled me to enter strange new environments, wonder at bizarre creatures and observe their alien ways. That's before even jumping in the water, if I'm in Portland.
     If you travelled to Nepal or Peru, you might expect to feel like a clueless foreigner, but in my experience there is nothing so astonishing as small-town UK. You encounter people who (nominally) speak the same language but, behaviour-wise, inhabit an entirely different planet. One which, in B&Bs throughout the land, seems to have an atmosphere consisting mostly of air freshener.
     Without a passion for UK diving, I would never have experienced the exotica of Weymouth, Wick or Seahouses. I would have spent my weekends in the bosom of North London, believing that watching Channel 4, doing brunch after the gym, and not having sex with your cousin were perfectly normal activities.
     UK diving is often described as a challenge, and it's more than your diving skills that come in for a battering.
     In my London-based existence, shops are there to sell you stuff. But if you jump off the RIB, dash up Chesil Beach, run into a shop in Portland and expect to buy a sandwich without being forced to miss slack on the M2, you're probably expecting too much.
     When the woman behind the till says she'll be with you right away, what she really means is that she'll be with you right after holding a 45-minute conversation with Mrs Parry about her dog's colic, and rearranging the change in the till.
     Where I come from, causing someone a delay is likely to result in a stabbing. So it's a chastening experience to realise that Tessie's acid wind problem comes higher up the list of priorities than you.
     For those of you nodding with approval at the friendly, relaxed attitudes of small-town folk, let me tell you about my club's recent trip to Alderney. The weather was fabulous, and we went racing over there from Portland on Ivor's big RIB Protector, filled with chocolate fairycakes and enthusiasm for amazing new dive sites.
     Our cylinders were filled by a local diver, a charming chap with a compressor at the back of his carpentry workshop. As he stood there, up to his knees in sawdust, and surrounded by portholes and brass ship fittings, we asked about good wreck dives in the area.
     "Wrecks... well, I don't rightly know," he said. "But you could try diving this bay, there are the remains of three steamships along the rocks."
     So we dived. The bay was filled with lovely but tedious white sand. Occasionally we discovered some attractive clumps of kelp. Then we found the rocks... and the vicious current that sweeps across them and drags you out to sea before you can squeal "delayed SMB".
     "Arhh, yes! That'll be the Races," chuckled the diver when we asked him about it later. "You don't want that bay. You want the next bay..."
     When it comes to helpful, friendly locals, the truth is out there - somewhere. Probably hidden under one of those elusive wrecks. We had a fine adventure, but not necessarily the one we were expecting. And reality? Less of a certainty, more of a moveable feast.
     If you regard diving as merely an underwater activity, you're missing out on a whole journey of discovery - the Zen of scuba. You can't make this journey as a tourist. It's here at home, in your heart.
     You might travel the world but, believe me, you'll never find anything that can enlighten you as much as your own backyard.