Churchill’s challenge

In 1941, in the harbour of Alexandria, a pair of British battleships were heavily damaged by Italian frogmen riding “human torpedoes”. The stealth raid sent shockwaves through the Royal Navy – and when Churchill heard of it, he insisted that the British work to create a similar device.

As the frogmen operated in small groups, it was clear that, to synchronise attacks, they would need a watch that was capable of functioning for several hours underwater. Other than those made for the Italian frogmen by Panerai, no such timepiece existed; but pocket watches used by members of the Royal Geographical Society in extreme environments offered inspiration. These tended to feature a specially designed screw back-and-front case, with the winding crown protected by an additional cap attached by a short chain.

This, then, is how the British wristwatches (pictured) appeared, with little development on a design that was by then more than a century old. The watches, containing a Longines movement used in Fleet Air Arm pilots’ watches, were bigger even than Panerai models, at 51mm across.

They were screwed Paneristi shut with a wrench, and thick wire was soldered on to accept a strap.

It’s likely that fewer than 50 of these were made, and to date just four are known to have surfaced – an amazing relic of a time when Britain stood alone and had to find its own solutions.