The first Hydro-Sub, released in 1965, was a fantastic technical achievement during its time, setting new standards for ultra-deep dive watches with its water resistance of 500 metres from its double gasket case construction, which was astonishing in the 1960s. It also featured a unique moveable crown protection to shield the crown from extreme conditions. Over 130 years later, Edox has brought back this legend of the deep with the new Hydro-Sub North Pole Limited Edition which played a vital role in world champion freediver, Christian Redl’s conquest as the first person to freedive in the North Pole in April 2015.