A FERRY service between Caithness and Shetland has been brought back onto the agenda amid hopes that it could help alleviate concerns over capacity on the current NorthLink service from Aberdeen.
Orkney operator Pentland Ferries and Gills Harbour in Caithness are behind the idea, which would see a ferry run between the top of the Scottish mainland and Shetland during the summer months.
It is expected that the potential service would need financial support from the Scottish Government, which could prove difficult to secure.
However, Pentland Ferries managing director Andrew Banks said the idea is an option that Transport Scotland could look into when considering the next Northern Isles ferry contract.
The issue was discussed this week with community and business representatives in Caithness and the concept is at a very early stage.
Fares on ferries to Shetland and Orkney from Aberdeen are set to fall next year as the Scottish Government introduces a new pricing structure based on a road equivalent tariff variant, but this is expected to cause capacity issues both for passengers and also for freight customers.
Banks said Pentland Ferries is due to replace its existing Pentalina ship on its one-hour Orkney-Caithness route next year and the vessel - which can hold eight artic lorries and 35 cars - could be used on a service to Shetland thereafter.
It is estimated that a trip between Caithness to Shetland would take up to six and a half hours, while the 70m catamaran ferry Pentalina would not be suitable for travel outside of the summer.
"I think it would relieve a lot of problems with cabin space on the Shetland boats. It would maybe promote tourism in Shetland too," Banks said.
He said the idea had previously been suggested to Transport Scotland but there was little interest in it at the time.
Banks said if "there's a demand for it, we'd certainly look at it in more depth."
But he admits it is unlikely to happen any time soon due to the limited prospect of the private company receiving financial support from the government, which already subsidises NorthLink's services.
"I just don't think it will happen, because we've been operating here now St Margaret's Hope [in Orkney] to Gills Bay for nearly 17 years without a subsidy, with no hope of getting a subsidy really," Banks said.
Chairman of Gills Harbour Ltd Bill Mowat said that "what is needed to get this possible project off the ground is a very clear indication that it would be welcomed from the Shetland end."
He said the idea was reignited recently after harbour vice-chairman Gordon Shearer heard from Shetland businesses during a visit to the isles that they would be interested in regular sailings if it was financially viable.
"At this end we think that a perhaps twice-per-week sailing direct to Shetland with Pentalina would be very beneficial to tourism, commerce from here and sports groups from Inverness northwards," Mowat added.
"Many hundreds of visitors every season to John O'Groats ask 'how can we get to the Shetland Islands' and I'm confident that some of these queries would be converted to actual bookings, if a direct ferry link existed."
Chairman of local transport body ZetTrans Ryan Thomson said future demand for ferry services is a growing concern locally and suggested that "all options" should be considered by the government in the months ahead.
A recent Audit Scotland report on ferry services in Scotland suggested that extra NorthLink sailings could take place to deal with demand.
"Capacity issues on our lifeline service was something we discussed at length at the recent ZetTrans meeting and the committee unanimously agreed that this issue needs addressed sooner rather than later," Thomson said.
"The additional tourism boost which the introduction of the RET variant on the route could provide during the summer months is anticipated to provide issues of capacity over the summer months, an issue the recent Audit Scotland report highlighted as something that needs addressed. We need to look at all potential solutions including the public sector.
"The government already have a subsidised lifeline service for the Northern Isles, however given the capacity issues we are expected to have over the summer all options should be considered by them."
A spokesperson for Transport Scotland said: "This proposal is a commercial decision for Pentland Ferries.
"Services to the Northern Isles have been subject to an extensive STAG (Strategic Transport Appraisal Guidance) study which is due to be published soon."