Tudor. A stainless steel automatic calendar bracelet watch Prince Oysterdate Submariner, Ref 9411/0, Circa 1976Tudor. A stainless steel automatic calendar bracelet watchModel: Prince Oysterdate SubmarinerReference: 9411/0Date: Circa 1976Movement: 25-jewel ETA Cal.2784 automaticDial: Blue, luminous block hour markers, baton quarters, white outer minute divisions, magnified date aperture at 3, polished 'snowflake' hands with luminous inserts, centre secondsCase: Brushed and polished tonneau form, screw down back with 'Original Oyster Case by Rolex Geneva', shouldered crown, bi-directional calibrated bezel with blue insert, No.847838Strap/Bracelet: Brushed 93150 Oyster linkBuckle/Clasp: Signed folding clasp, stamped S T6Signed: Case, dial & movementSize: 39mmThe unusual shape and large size of the luminous hands are a design feature initially introduced to improve legibility whilst diving in low visibility conditions. Predominantly used in its early years by divers in the French military, the "Snowflake" Submariner soon became an icon on the civilian market and has become one of the most collectable vintage Tudors made to date.