Rare WWII H Golay Royal Navy Fleet Air Arm HS 4 Navigation Military Watch

Rare WWII Vintage H Golay Royal Navy Fleet Air Arm HS 4 Navigation Watch. The white enamel dial with black roman numerals with matching blue steel hands is signed 642 H. Golay & sons Ltd London with outer rotaling bezel that operates as it should. The jewelled manual wind movement is working well and serviced by us, number matches through out the case. The steel screw back 62.2mm case is fully numbered in the back 179 swiss made. Dont miss this one! This type of watch was used by the Fleet Air Arm in Fairey Swordfish aircraft during WWII. The 1941/1942 Admiralty Manual of Navigation describes this style as a beacon watch, only to be used in aircraft fitted with an R1147 radio receiver.


Aircraft carriers were equipped with a revolving beacon that continuously transmitted second pulses, making a full rotation once per minute. The crucial feature of this system was that the beacon emitted a different sounding signal when it was pointing due north.


Prior to launch, (these planes were catapulted into the air), the observer would tune the radio receiver to the beacon and set the bezel of the watch so that zero on the outer scale and the tip of the second hand aligned precisely at the time of the northern signal. When returning to the carrier, the observer on board the aircraft would turn on the radio and listen for the beacon's signal.


The strongest reception would be experienced when the beacon was pointing directly at the aircraft and, using the watch, the aircraft's position relative to its carrier could be found and the pilot given the course to take. The great benefit was that these slow aircraft could home in on their carrier from up to 100 miles away without sending out radio signals that may betray their position to the enemy.


In 1937 Hector Golay & Son Ltd of London were the only importers of Universal watches and chronographs and supplied the Ministry of Defence with dashboard mounted navigation watches such as this example. H^S.4 designation is described as a 'Dashboard Watch'.