Why the F-91W keeps ticking

If you’re one of the millennials, you’re expected to not know about the Casiotron almost by definition – but you probably do. It was a Casio digital watch first sold in October 1974, and its claim to fame was that it was “computerised”, able to calculate the number of days in a month (but not leap-months). Its functions, revolutionary for the time, became the foundation on which Casio built its future digital watches – leading up to the unlikely hero called F-91W.

A tried and true style great for casual wear. With its daily alarm, hourly time signal and auto calendar, you’ll never need to worry about missing an appointment again.

That’s the exceedingly simple premise with which the F-91W is marketed. There are no frills: the watch shows the time, date, has a stopwatch and an alarm clock. It’s mildly water resistant – it’s okay when water splashes on it but not if you shower with it – sports a resin band, is powered by a CR2016 button cell that lasts for seven years, and weighs 22 grams. It’s hard even to tell if Casio intended on making a statement with the thing when it first came out – in 1991 – any legacies used in its design having been flattened into its unassuming timeface. But make a statement it has.

On August 17, a powerful blast ripped through the popular Erawan Shrine in Bangkok, killing at least 20 and injuring over 120. Investigations into the identities of those responsible led the Thai police to an apartment in the city’s eastern suburbs on August 30. Bangkok Post reported that apart from explosive materials and wiring, four wristwatches were also found. Four Casio F-91W wristwatches.

In the post-9/11 period, if a captured terrorist was found to possess an F-91W, the person was assumed to have been trained in bomb-making. At least so went the saying – and it wasn’t hard to believe considering the F-91W was (and is) cheap, easy to find and easy to operate. According to a WikiLeaks dump released in 2011, Al Qaeda gave the watches to trainees in terrorist camps, where they learnt to press the innocuous things into the service of crude detonators, in Afghanistan.

One of the documents in the Gitmo Files dump. The watch’s attributes are described in the footnote. Source: Gizmodo
One of the documents in the Gitmo Files dump. The watch’s attributes are described in the footnote. Source: Gizmodo

The F-91W’s association with Al Qaeda was prominently established following the Denbeaux study, which profiled 517 Guantanamo-Bay detainees and published its reports from 2006 through 2009. It found a lot of the detainees charged with working with or setting off explosives also owning, or even having been captured wearing, the F-91W (or its silver-coloured sibling A159W). Before that, the watch is first thought to have made an appearance in connection with terrorist activities with the foiled Bojinka Plot in 1995, aimed at assassinating Pope John Paul II and bombing many Asian and American airports.

The F-91W scores because it’s ubiquitous and the watch doesn’t need serious modifications to play its part as a timing device in a detonator, so when a raid is imminent the terrorists can walk away wearing it and claim it’s just a watch.

Unfortunately, this trait fed the feds’ paranoia after 9/11: they weren’t prepared to believe that it could be just a watch, especially around the wrist of anyone being shifty in the Middle East, and they were prepared to believe that possessing it was enough to all but indict the wearer. Yet, it was and is worn by millions around the world (including this writer). Casio doesn’t publicise the sales numbers of the F-91W but said in 2011 that it remains a “huge seller”.

And it will probably endure, too. The F-91W’s notoriety was hedged on a forgettable application but its mainstream success owes to what that application prized as well: function over form, doing it what it said it would, not doing anything that wasn’t promised, earning it the enviable sobriquet as a “modest masterpiece”.