The tunnel, if constructed, is assumed to make landfall on South Ronaldsay. In 2005, the tunnel was discussed, and then a total bill of £100 million was mentioned. There has not been so much discussion after 2005.
With recent developments of the renewables industry in the Pentland Firth, the idea of a tunnel has lost ground, though there have been discussions of the construction of a bridge over the top of a Pentland Tidal Array.
- David Lister (5 September 2005). "Islanders see a brighter future with tunnel vision". The Times. Retrieved 12 July 2007.
- John Ross (10 March 2005). "£100m tunnel to Orkney 'feasible'". The Scotsman. Retrieved 5 February 2012.
- "Isle tunnel plans under spotlight". BBC News. 9 March 2005. Retrieved 8 June 2009.