A recent visit to my local caravan dealer confirmed a design trend that I’d suspected: washrooms are getting bigger. And bigger. I’m sure that one model I viewed was 50% washroom. It was considerably bigger than my bathroom at home, and perfectly adequate for the sort of foam party that Hugh Hefner would throw. Wood panelling and chrome-surrounded white porcelain fittings, and a multi-head-power-massager-cubicle had jets positioned in a multitude of intriguing places.

I’ve always been content with the more conservative toilet and washing facilities in my seven-year-old tourer. A cassette toilet sits in a tiny plastic cubicle alongside a basin with an extendable tap that doubles as a showerhead. Using it requires some contortions and could, I suspect, flood the rest of the van. But who cares? I’ve never used it. Most site facilities are so well maintained, I’m happy to use them instead.

It is slightly odd to conduct ablutions in the proximity of strangers, but I’ve never found it traumatic. Until last week, that is.

Imagine the scene: it’s 7am when I make my bleary-eyed way to the shower block. I pick a cubicle, close the outer door and undress in the little changing area that precedes the shower enclosure. I carefully stack my clothes on the plastic fold-down seat behind the door.

Now naked, I realise that I need the loo. Fortunately, my shower is at the end of the row, and the adjoining cubicle is the first in a line of toilets. I then make what turns out to be a major error of judgement: why bother dressing just to nip to the toilet?

I listen carefully and conclude that no one else is in the block. I lift the drop-down seat and gingerly open the shower door to double-check. The coast is clear, so I dart from the shower into the adjoining toilet. As I do the shower cubicle door closes with an ominous thud behind me.

When I emerge from the toilet, I push the shower door to open it, but it won’t budge. The penny drops. As has, it transpires, the fold-down seat. No amount of frantic shaking will dislodge it. I freeze, separated from my clothes, towel and modesty.

Then someone approaches; his footsteps echo through the open shower-block door, leaving me seconds to make a plan. Should I try to scale the door or limbo under it? Should I hide in the toilet until cleaning time or swallow my pride and call for help?

Then I spy a mop at the far end of the block. Eureka! I streak through the block, grab the mop, streak back and push the handle under the door. I dislodge the seat enough for me to force the door open and collapse inside. It all lasts 45 seconds and ends as a startled fellow camper enters.

If that person was you, I apologise for the sight that greeted you.

Meanwhile, I’m off to my local caravan dealer with one feature uppermost on my wish list.

Visit Martin’s website for information about him, his books and his property training weekends, and follow his adventures on Twitter