It’s been a very damp winter and I normally leave all the sea-cocks open when the boat’s laid up, to add some extra through ventilation. But this season I forgot and when I went aboard yesterday was horrified at the amount of mildew over – fortunately – the formica surfaces. I boiled a kettle and wiped all down then became aware someone else had already been aboard.

My automatic lifejacket – never used in anger – was lying on the cabin sole, deployed but long ago deflated.

I knew the damp must be the culprit, but it took YM’s technical editor, Chris Beeson, to pin-point it more accurately: the salt water tablet which activates the inflation bottle must have corroded in the briny atmosphere.