Omega introduced the Seamaster 300 in 1957. A very small number of these watches were made for the military. In 1967 until approximately 1970 and custom designed by Omega, watches were issued to members of the British Royal Army and Navy.
There are some special features to the present watch, which set it apart from standard production. The case has distinctive curved and beveled lugs and fitted with fixed spring bars. The dials feature an encircled “T” designation, signifying the use of tritium for the luminous hour markers and hands. The broad, sword-shaped hour and minute hands were also specially designed. The crown was screw down as opposed to the snap down as found on standard production. The case back was engraved with military markings of the military branch code, issue number, and year of issue. The "W10" designation indicates that this Seamaster 300 was issued especially to the British Royal Army.