Tudor military Submariner Ref 7928/0 a rare and interesting stainless steel wrist watch of US naval interest dated III.64 circa 1967. Dial: black 'T Swiss T' marked 200m=660ft, rotor, self-winding luminous dots, baton and dagger numerals, luminous Mercedes hands, sweep centre seconds. Calibre: Auto-Prince automatic,17 jewels, butterfly rotor. Case: stainless steel tonneau-shaped, revolving bezel calibrated to 60 units, screw-down crown and case back with naval seal inscription U.S. Nswg-2 020 Feb.68, inner screw-back dated 11.67. Case number:. Closure: khaki Nato fabric. Dimensions: 39 mm diameter. Signed: case, dial and movement. Accessories: none. Provenance: Gardiner Houlgate, UK, 24 June 2020, lot 55, illustrated. Private collection, Queensland, acquired from the above. Footnote. Accompanied with a scanned letter image from renowned engraver Charles R. Scarr who examined the case back of this watch and concluded that it was engraved using a pantograph and that in his opinion the Navy seal inscription was very likely engraved at the point of issue to the U.S. Navy in 1968 - naval special warfare group (Navy seals). In 1961 President John F. Kennedy received the recommendation from Admiral Arleigh Burke, chief of naval Operations, for the establishment of guerilla and counter-guerilla units in response to the growing need for unconventional warfare in Southeast Asia. These units would be able to operate from sea, air or land. This initiative was the beginning of the Navy seals whose mission was to conduct counter guerrilla warfare and clandestine operations in maritime and riverine environments.