By Kevin Young
Entertainment reporter, BBC News
The Shipping Forecast can be heard four times a day on BBC Radio 4, giving details of conditions in the seas around the UK, Ireland and beyond.
Each broadcast attracts hundreds of thousands of listeners, many of them with no connection to coastal waters - so what is its enduring appeal?
There is a certain mystical quality to the names of the 31 marine areas included in the Shipping Forecast.
The sea is divided up into sections with names such as Viking, North Utsire, Humber, German Bight, Lundy and Fastnet.
And although references to "north veering north-east, three or less" and "smooth or slight" might mean nothing to land-based listeners, they are hugely significant to sailors who tune in to Radio 4.
"What we're interested in is the wind force direction and how quickly it's going to change," says Captain Paul Wood, who regularly sails cross-Channel ferries for P&O.
"The forecast will tell us what we're getting, but we can also find out what's causing that problem for us.
"If it says 'low Finistere', I know where that is. And if it says 'moving deep and north-east to Forties', I can immediately get a mental picture of where it's going and what the weather will do.
"I know the sea areas like the back of my hand and they make perfect sense to us."
Radio 4 controller Mark Damazer describes the forecast as "baffling".
"It scans poetically. It's got a rhythm of its own. It's eccentric, it's unique, it's English.
"It's slightly mysterious because nobody really knows where these places are. It takes you into a faraway place that you can't really comprehend unless you're one of these people bobbing up and down in the Channel."
The forecast appears daily on Radio 4 at 0048, 0520, 1201 and 1754
The broadcast was already part of the Home Service when it was rebranded as Radio 4, 40 years ago this week.
The schedule for the first day of Radio 4, on 30 September 1967, has an entry from 2345 to 2348, describing a "forecast for coastal waters".
Produced by the Met Office in Aberdeen and scripted for the BBC's weather presenters, it is now nine minutes in length.
"It's about the only bit of blurb that we read without having any input. Everything else is ad libbed, and this is scripted," says weather presenter Rob McElwee.
He prefers to read the bulletin "cold", rather than rehearsing it, and uses his thumb or a pen to keep his place on the page.
"The art of the writer is to try to make it fit into the artificial sea areas, even though the weather may not fit there," Mr McElwee adds.
"Sometimes you get some pretty bizarre occurrences - the south of North Utsire, west Cromarty and east Forth all combined in one area, which sort of defeats the object of having the areas in the first place. But sometimes it happens."
The 31 areas were brought to life a decade ago when Magnum photographer Mark Power took a picture of each and turned them into a book.
He was inspired by a tea towel showing the coastal divisions, which he had bought in an RNLI charity shop in Great Yarmouth.
McElwee often reads the forecast at the end of a 12-hour reporting shift
"These are quite common now but I'd never seen one before. It did spark off certain pictures in my mind of these imaginary landscapes that I had built up in my head over all of these years."
He spent four years travelling around the coast, using his own savings when his applications for grants were turned down.
"If I'd actually sat down and thought about the logistics, I would never have started. But I guess, in the end, I just didn't, and I thought I would see how it went."
He put a caption on each image, giving the 0600 forecast for the day when that photograph was taken.
A "book-of-the-week" recommendation in The Observer led to a first print run of 2,000 being snapped up "in about three weeks", Mr Power says, with two subsequent editions also selling out.
"Ten thousand copies doesn't sound very much, but I'm not David Bailey - I wasn't anybody, in fact.
"I'm very proud that there's a serious photography book on the shelves of 9,500 people who wouldn't normally buy a book like that."
But he admits many people did write to him, expressing disappointment that he had gone ahead with the project.
"I suppose it was like making a movie of a book and realising the characters are not supposed to look like that."
So does the forecast have a future on Radio 4 in these days of satellites, mobile phones and computers?
Mr Damazer admits to being "slightly worried about anybody who is bobbing up and down in the Channel whose sole way of keeping from sinking is by listening to us on long wave".
"My advice would be to invest in a GPS system," he jokes. "But I still won't take it off because it's a glory of its own."