The Rolex Oyster is the watch associated with Rolex’s pioneering waterproof Oyster case, introduced in 1926.
Its case used a screw-down bezel, case back, and winding crown to create a sealed enclosure. Rolex founder Hans Wilsdorf promoted the design as a major advance in wristwatch durability, and the name “Oyster” referred to the case’s resistance to dust and moisture.
The Oyster was not a diving watch in the modern Submariner sense. It was a general-purpose wristwatch design that established the case architecture later used across many Rolex families. In 1927, Mercedes Gleitze famously wore an Oyster during her attempted swim across the English Channel, helping publicize its water resistance.
The Oyster should not be confused with the Oyster Perpetual, which combines the Oyster case with Rolex’s automatic winding system. The Rolex Submariner came much later, in 1953, as a purpose-built professional diving watch.