At the start of WW2 in September 1939, the Admiralty were already concerned about the security of the fleet based at Scapa Flow. Subsequently, later that month, a number of vessels were moved to Loch Ewe. Although, it was less exposed to attacks by aircraft, submarines still posed a dangerous threat.
In mid-September, Churchill arrived in Loch Ewe aboard HMS Nelson to inspect the crew of HMS Ark Royal who had taken part in the sinking of U-39; the first U-boat lost in WW2. This was hailed as a great boost to morale.
Churchill also discussed the best option to locate the fleet until Scapa could be secured. He then came ashore and stayed at Pool House taking a stroll beside the River Ewe whilst his white boiler suit was laundered for him. He was collected by Captain Alexander Matheson RN who drove him back to Inverness. Alexander Matheson would become Lord Lieutenant of Ross-shire, as would his daughter, Janet Bowen.
On the 4th December 1939, U-31 laid mines around the entrance to Loch Ewe. HMS Nelson detonated one of the magnetic mines and was holed sufficiently to cause her to list. There were no casualties but 74 sailors were injured.
Anti-aircraft defences were rushed to Loch Ewe and permanent anti-aircraft sites were established around the loch. The base became known as HMS Helicon.
Sea defences were also installed including a guard loop which detected vessel movements by changes in the electrical field. An anti submarine net was also put in position across the loch. There were flares on the surface buoys that would be triggered if there was any attempt to penetrate it.
Indicator nets were made of steel and anchored to the sea bed. They were mainly a means to discourage enemy submarines from entering although sometimes mines were attached to the nets in an effort to destroy the submarine.
The design and manufacture of the Loch Ewe nets was carried out at the Rose Street Foundry in Inverness (now a gastro pub).
The boom was anchored by very heavy concrete weights.
A gateway opened by two trawlers allowed “friendly” ships entry. These boats had “horns” enabling them to lift the weights. The net was suspended on the surface by a line of large buoys.
The boom defence was instrumental in protecting the many merchant and escort ships that took part in North Atlantic and Arctic Convoys whilst anchored in Loch Ewe. The Coastal battery and nets must have been a welcome sight to returning sailors after arduous journeys in severe weather and with the ever present danger of attack.
The boom base remained open after the war finally closing with the loss of fourteen jobs on the 10th March 1978.