The Corum Bubble was introduced in 2000 as a playful 'fun' watch, developed under the reign of the late Severin Wunderman. The Bubble's main element of distinction is of course the over-sized bubble-shaped sapphire crystal, which is said to have been inspired by the original Rolex Deep Sea watch. After a few years of absence the Bubble made a reappearance at the 2015 BaselWorld show.