One of the great pleasures of pottering round the coast is boatspotting.

I played a little game of this with a friend in July when we were bobbing about the Eastern Solent. We tried to trump each other in recognising boats of yesteryear: that’s a Contessa 35; that one’s a She 31, oh, there’s a Pat Patterson-designed Heavenly Twins cat.

It’s a great way of passing a slow afternoon.

Last month I sailed past this unusual one-off on the River Dart. The owner, who had been somewhat preoccupied with trying to get the engine going (it appeared to be suffering a bad case of fuel starvation), told me briefly that it had been designed in the 1970s for the Fastnet Race. I think he said the designer was French.

It’s an absolutely extraordinary shape by modern standards, and very redolent of an era. It had two features that are distinctive but quite dated: tumblehome and reverse sheer. As you can see it also quite a tapered stern.

Looking at the photos afterwards I kept wondering about the concept of reverse sheer. What was it all about?

How did it go from the straight sheer of John Illingworth’s Myth of Malham, the Fastnet Race winner in 1947, through later the rather pretty reverse sheer Illingworth/Primose design Outlaw to more extreme versions such as this 30 years later, only to die out completely?

What was the purpose and why did it become outmoded?

So I called a man who might know: the encyclopaedic designer Stephen Jones.

“It started with Illingworth when he designed Myth of Malham,” says Stephen, “and he wrote about it in his book “Offshore”. I think the idea was vaguely about headroom and keeping freeboard in the middle of the boat so it was higher out of water and there was more accommodation.

“But the question is what do you do with the stern? So you cut it away. You pare away at the ends. Illingworth said in his book that this was the way boats were going to be from then on. It was quite misguided of course. Later boats went the whole way, pre-IOR, and they were hideous to look at.”

I can’t help but agree. Marked reverse sheer can make a yacht seem humpbacked and bellicose. It’s not an elegant look.

But, adds Stephen, “if it’s done moderately it’s sort of OK”.

There were quite a lot of famous and now classic yachts that did have moderate reverse sheer. In the office we can immediately think of three: the Illingworth/Primrose design Outlaw; the RAFYC’s first ocean racer, the cold-moulded Dambuster, also an Illingworth/Primrose design; and Jack Giles’s Sopranino.

Stephen Jones also says J. Francis Jones did a few with reverse sheer. ‘Jack’ Jones, who worked on the East Coast, was pretty versatile and designed all kinds and shapes of yachts including a lot of motor sailers and MFVs. And Stephen also cites Fred Parker’s Fizz, which I don’t know and will need to research a bit more in our archives.

I find it a really interesting subject and am interested in any comments or other examples.