Water and watches really don’t mix. Even the smallest amount of moisture inside a mechanical watch can corrode the gears, springs and screws essential to its operation and irreparably damage the dial, hands and decorative elements.

So for more than 150 years watchmakers have been selling timepieces said to be protected from water, beginning with pocket watches like L’Impermeable, introduced in 1864 by Alcide Droz & Sons of St. Imier, Switzerland.

But it was the onset of World War I — just as the watch itself was transitioning from the pocket to the wrist — that accelerated the need for water-resistant watches. In 1918, Charles Depollier, working with the Waltham Watch Company of Massachusetts, introduced the Field & Marine watch, which a government official told the U.S. Secretary of War was “a design of waterproof case in which a watch could actually run for several weeks under water.”

In 1926 Rolex patented the Oyster case, marketing the model as the world’s first waterproof watch. Both the Rolex and Waltham timepieces depended on screw-down crowns, screw-fit case backs and protective rubber gaskets to keep water out.

And in recent years both Rolex and Omega have created watches that operated during visits to Challenger Deep, which — at 10,935 meters (35,876 feet) — is the deepest known point in the ocean. During development, the brands said, those watches were tested under pressures that exceed anything found on earth.