As a four-year-old, I was given my first swimming lesson by my great-uncle. He threw me into a pool. It was literally sink or swim. I've thought of him ever since as having been slightly batty.

It turns out, however, that great-uncle Manny was on to something. According to Rick Kiddle, a former British champion triathlete, now a tutor and assessor for the British Triathlon Federation (and my swim coach for the next hour), the worst way to teach children to swim is to put them in armbands. "You are not letting them learn the fundamentals of how their body reacts to water," he tells me. "If you get them to scull their arms, they develop a feeling for the water and from there they can learn how to float, tread water and stay upright."

I did stay upright as a four-year-old (I don't remember how – probably with mad windmilling of my arms), which propelled me on to a life aquatic that now includes the regimen of a daily morning swim at my local baths. Given that I happily swim a kilometre a day and recently splashed my way from Asia to Europe, will I really gain much from training with Kiddle?

Well, yes, as it happens. It is all too easy to fall into bad habits when swimming on your own, and mine become apparent about 10 minutes into our session. We begin with two leisurely lengths, Kiddle closely watching my every stroke. I flail about when I am asked to swim 100 metres flat out, my technique going to pot.

"You've basically got a good stroke," he tells me, "but if I'm to nit-pick ..." And nit-pick he does, expansively so in the report he prepares for me later. My head position is OK and my hips are in a good position, but my body snakes from side to side, I'm too flat in the water and I need to rotate my body while extending my arms and gliding, though without overdoing the roll, because I can't allow my arms and elbows to drop. And that's just for starters. My hand timing is OK, but my hands should enter the water earlier and in the eye line; my initial "catch" with my hand in the water is too low and hurried. My hand entry is also too deep, and when I pull my hands back for another stroke, they move across my body unnecessarily (hence the snaking, and also the pain I get in my left shoulder). On the plus side, my hands are exiting at my thighs and my "recovery" arms are in a good position.

If all this seems a bit much to take in while standing in a pool, I can confirm that it most certainly is. Especially when advice about my kick and breathing is nearly as extensive. However, the drills Kiddle has devised help to implant it in the mind. "People learn differently," he says. "For some, telling them works best; for others, it's visual [watching a demonstration and repeating]."

I seem to be somewhere between the two. We work through various manoeuvres, from how to kick properly (Kiddle slips into the water for this, showing me how it should come from the hips, not the ankles) to elongating the stroke and thus gliding through the water – by doing this, I reduce my stroke rate from 26 per length to 16, preserving energy. One drill has me attempting to swim a length with my hands balled up into fists – just try it if you don't think it'll be hard – then swimming back to the other end normally, allowing me to appreciate afresh the effect of using my hand as a paddle. This, again, is about getting a better "feel" for the water, back to the very basics of being thrown in at the deep end, so to speak.

drive from www.independent.co.uk