will add vid on Friday

My addendum to the "If you've got it, flaunt it" rule is this: "And if you haven't got it, disguise the fact by wearing long baggy swimming shorts on the beach. Right down to your knobbly knees if possible. And have the good manners to cover the rest of your Dad Bod in a Keep Calm And Kill Zombies t-shirt. Or a vest."

I know my addendum rolls off the tongue with all the grace and beauty of a bus full of drunk Scottish football fans rolling off a cross-channel ferry, but it has always served me well. Besides, as one of those middle-aged men who still thinks he's going to jack in his high-powered career and generous salary and move to Cornwall to surf and have barbecues, I'm kind of wedded to the idea of what are known as "board shorts". And they tend to be knee-length.

As luck would have it, our old friends at fashion website Mode have made another of their 100 Years In Three Minutes films and this time they've looked at men's swimwear, from 1915 to the present day. What's obvious is that you'd have to have been born in that year to have encountered anything other than a version of what we have today: shorts. By the time you hit the 1930s, the striped woollen one-piece was already a thing of the past and men on beaches were bearing their chests quite happily. What's also clear is that nobody in their right mind would ever wear trunks/Speedos/"budgie smugglers". They don't even feature.

No, all that has really changed is the length of the shorts, and even that's just a matter of a few inches here and there. So the shorts were shortish in the 1950s, shortish and belted in the 1960s, shortish and Paisley-patterned in the 1970s, shortish again in the 1980s and then longer in the 1990s, which is clearly when my tastes were formed. That would be about right actually: I was living in Sydney at the time, the period at which I was as close as I am ever going to get to a life of surfing and barbecues. And probably a generous salary too.

So if fashions in men's swimwear have barely changed in 80 years, that makes it fairly fallow ground for designers. Understandably, then, the names of the few specialists there are don't exactly trip off the tongue. Ever heard of Orlebar Brown? Thought not.

They seem to be the go-to guys though, and charge around £130 for very natty, tailored swim shorts of various lengths. Most are named after manly kinds of pooches – Dane, Bulldog, Setter, Springer, that kind of thing – though you have to assume their wearers have moved on from doggy paddle and mastered a few other strokes. As well as plain colours and headache-inducing swirls, they also do shorts bearing photographic prints. These will cost you £225. One shows an aerial shot of a bunch of sun worshippers sitting round a pool. Not a vest or even a Dad Bod in sight, mind, but you can't really blame them for that. Happy hols.