Inspired by the vintage lines of Tudor's first dive watch from 1954, the Black Bay Marine Nationale diver is a refined, contemporary take on the original Tudor Submariner. The 41mm stainless steel case features a glossy midnight blue rotating bezel with white diver function numerals. The matt black dial has large contrasting luminescent hour markers and the signature angular 'snowflake' hour and minute hands first introduced by Tudor in 1969. Another nod to its vintage roots is the large winding crown with a midnight blue insert. The self-winding Swiss movement, calibre 2824, has a 38-hour power reserve and is waterproof to 200m. This Tudor Heritage Black Bay Mariner Nationale dive watch is offered on a choice of a stainless steel bracelet or blue leather strap, both with an interchangeable black/blue fabric strap.