Rolex Deep Sea Dweller 126660DBLUE 2019 [Preowned]Overview The Deepsea is where Rolex's dive watch engineering reaches its operational limit: 3,900 metres water resistance, achieved through the Ring Lock System a compression architecture that prevents the case from buckling at depth rather than simply sealing it against water ingress. The 126660 in D Blue is the generation introduced in 2018 with the Calibre 3235 upgrade, retaining the case architecture of its predecessor while adding 70 hour power