Hi MB.
Believed to be RNAS Hatston, Orkney, (HMS Sparrowhawk). Early in 1939 the Admiralty asked for advice from Capt Fresson of Highland Airways regarding the establishment of an airfield in Orkney. Fresson suggested the site at Hatston but commented that the drainange of the site would require Tarmac runways, as would any other in the islands, to be useable all year round. This was very remarkable thinking at the time and even more surprisingly, the Admiralty accepted it! The airfield opened just before the declaration of WW2 but I don't have an exact date. First operational use was Nov 1939 by 804 squadron.
Spiney