I’ve only been bent twice. Once was on Mull, after a too-rapid ascent from 30 metres. The other was on Hampstead Heath in London during a ten-mile Sunday morning jog.

The symptoms were identical – a shimmering disturbance to my vision, like sunlight on water.

The first time, our diving officer called in the local GP. If he’d been sure it was a bend, they’d have rushed me to Fort William in a chopper. If he’d been sure it wasn’t, he’d have referred me to SpecSavers.

But since he wasn’t at all sure about anything, he told me to drive twenty miles to Craignure, catch the next ferry to Oban and report to the Cottage Hospital. If you ever needed an illustration of the drawbacks of Compromise, this was it.

I suppose if I’d suffered a brain embolism on the Tobermory coast road, the worst scenario would’ve been a bucket or two of mutton mince.

Anyway, I turned myself in at the hospital where they told me I was to be ‘under observation’ for twenty-four hours.

During that time, as far as I could make out, I was under observation only by Daft Duggie, a hoary old crofter from Eig who had the next bed to mine. It was his first ever trip to the mainland. He’d been bitten on the finger by a psychotic ewe and now it had to come off.

By Island standards he was remarkably sophisticated. He even used an underarm deodorant – although he did apply it to the outside of his cardigan.

I suppose I could also have been observed by Auld Willie although he was pretty well out of it. He had the next bed to mine on the other side, and died on the stroke of midnight night with a weird rattling sound.

But why am I telling you this?

As I said, my second bend occurred a year later in North London.  I hadn’t dived for weeks – mainly because my consultant had attributed my first bend to a PFO (not a strange hybrid of flying saucer and militant Middle Eastern political organisation, but a small hole in the heart).

He’d forbidden me to dive deeper than 10 metres. In those days I dived exclusively in UK waters. I mean, how many used prophylactics can a man swallow?

So in a way, Bend 2 was a liberating experience. I immediately flew to Gozo where my first dive was to 42 metres. And I’m still here to tell the tale.

Not that I’m blasé. Bends really do happen. I’ve seen them. There was the Italian in Malta who surfaced after about three hours spent underwater spearing anything that moved.  Then he turned green. It would have looked quite attractive on a fireplace or a work surface, sort of mottled and marbley, but on a human it was really alarming.

The nice man at the recompression facility called it subcutaneous emphysema. It was a bend. Not life threatening, but for two days he crackled when you touched him.

Nor will I ever forget the extraordinary case of Fat Alf Miggins, a diver of a legendarily-modest intellect who failed his Open Water theory paper eleven times.

Then he put on his computer upside down, so that what he thought was 19 meters was actually 61, and suffered an acute neurological bend.

When he finally regained consciousness, he began rattling off seven-digit prime numbers and reciting the love poems of Catullus. He’s now Professor of Cosmology at Harvard.

Which suggests that ‘bends’, like the twists in the road after which they were presumably named, can go either way.

May all your bends be right ones.