It will deliver superfast broadband to some of the most remote island communities as well as the mainland.
Cable has now been laid on seven routes so far: Largs-Millport, Kilchattan Bay-Millport, Rothesay-Toward, Kilfinan-Lochgilphead, Campbeltown-Shiskine, Jura to Port Askaig and Ardgour-Onich. Teams are currently in Orkney and then scheduled to head to Outer Hebrides next week.
The subsea cabling forms a vital part of the £410m Digital Scotland Superfast Broadband initiative and will bring fibre-based broadband to many parts of Scotland for the first time.
The cabling forms part of the £146m Highlands and Islands project being led by Highlands and Islands Enterprise (HIE). Funding partners include the Scottish Government, HIE, and Broadband Delivery UK. BT, the selected private sector partner is investing £19 million in the area. The subsea project aims to deliver around 250 miles of cables to link island communities.
Managed by BT, the deep-sea work will be carried out by Orange Marine's cable ship Rene Descartes using the ship's submersible plough and remotely operated vehicles to bury the double-armoured cable in the seabed, where seabed sediments allow.
Deputy First Minister Nicola Sturgeon said: "This is one of the most ambitious broadband infrastructure projects ever to have been undertaken and will see 95 per cent of premises in Scotland covered by 2017/18."