This month a new film version of one of my all time very favourite most treasured books is being released. Swallows and Amazons

Better drowned than duffers, as Father says in his telegraph to his would be sailing-explorer children. If not duffers, won’t drown.

Don’t do anything stupid, and you won’t drown. If you do do something stupid, you might as well be drowned.

That’s a quite a nice summation of how I feel about this film. Don’t do anything stupid with it, and I won’t wish everyone involved was drowned.

However.

There are some things… I generally understand why they have changed Titty’s name to Tatty, although I am sure I will experience deep confusion in the cinema and continue to refer to the character as Titty to the confusion of anyone who sees this film without knowing the books. I think it’s a bit silly, and if kids go on to read the books they’ll be confused, but I get it.

I also understand why they have added what appears to be a dramatic plot element by way of a couple of shady characters who seem to be chasing and ultimately kidnapping Captain Flint. The trailer shows Rafe Spall, as Captain Flint, making his escape clinging to the outside of a steam train, and later being tied up and dumped in the bottom of a boat. Ho. And indeed hum. I can understand why the filmmakers think they need some exciting plot, I just think that they're very likely to be wrong.

The deep joy of Swallows and Amazons is that these are ordinary children living ordinary lives (yes, nice middle class English ones) playing games and going camping and using their imaginations to make these activities into a much bigger and more exciting world. The frozen lake in Winter Holiday turns the houseboat into Nansen’s Fram and gives them the opportunity to journey to the North Pole; in Swallowdale they name one of the fells the Kanchenjunga, and mount an expedition to climb it; and in Pigeon Post they train racing pigeons and search for gold. Even the two most fantastical books in the series, Peter Duck and Missie Lee are commonly understood to be stories that the Swallows and Amazons make up about themselves to while away time when they’re not able to be out exploring and pirating.

‘Well,’ said Nancy. ‘You know what it’s like. Dark at tea-time and sleeping indoors: nothing ever hapens in the winter holidays. And we had to think of something that we could do without our ships… So we started a Polar epedition. We sleep in the Eskimo settlements at night, the same as you, and we’ve been building an igloo of our own…’ ‘The idea was that as soon as we could we’d go to the North Pole over the ice,’ said Peggy. ‘Wev’e got a splendid North Pole.’ Only, the beastly Arctic won’t freeze,’ said Nancy, ‘and the holidays’ll be over in no time.’

It wasn’t like the Famous Five, where they had to wait for adventures to fall into their laps; or Mallory Towers or Chalet School, where they all got sent to boarding schools in Cornwall or Austria and Switzerland. It wasn’t like The Weirdstone of Brisingamen because there were no wizards; and it wasn’t like Anne of Green Gables because you didn’t have to wait for a Gilbert to show up. Anyone could have the kind of adventures the Swallows and Amazons have, and I spent the greater proportion of my childhood trying. Captain Nancy was my role-model, and so I learnt to signal in morse and semaphore, and did terribly destructive things to our one little ash tree with a pen knife as I tried to make bows and arrows that would actually work. I went to sailing club one summer, and the fact that it was all cliquey and exclusive hurt my tiny heart. The Swallows and Amazons would never have made the Ds feel so left out. And I climbed the Kanchenjunga (the Old Man of Coniston): telling me that we were walking to a place in Swallows and Amazons was a sure-fire way to get me to walk anywhere in the Lake District as a child.

And so I’m worried about the spies spying on Captain Flint, and the added drama that brings. In the book, gossipy locals tell stories about what Captain Flint has brought back with him from travelling the world and a couple of them convince themselves that there’s a chest full of money on his houseboat and break in to steal it. It is that simple - but because it’s seen through the eyes and imagination of a small girl at night on a lake, it is all very exciting and adventurous. Swallows and Amazons really doesn’t need more than that. Trust it.

Towards the end of Swallows and Amazons Mother is questioning John about some of his crew’s activities, and she says, ‘Don’t you think that was very nearly like being duffers.’ This exciting new plot development might very well pay off, in which case, no one will drown. But - better drowned than duffers, and I can’t help but wish they hadn’t made this change.