It promises to transform life in some of the nation’s most remote communities and provide a massive boost to the marine economy.

Under a three-year plan, Crown Estate Scotland (CES) will invest £70 million to fuel coastal regeneration, expand green energy and support sustainable food production.

The body, which manages land and property on behalf of Scottish ministers, is also aiming to ensure new wealth is spread as widely as possible.

Amanda Bryan, CES Chair, said: “Over the coming years we want to invest in property, natural resources and people to generate lasting value.

“From growing shellfish to new ways of farming, regenerating coastal communities to building Scotland’s blue economy, our focus will be sustainable growth that benefits all.”

CES chiefs want to make it easier to invest in cutting-edge forms of renewable energy, including tidal, wave and floating wind power, while fish farming and other fast-growing aquaculture sectors have been earmarked for research support to help them operate sustainably.

Scotland’s ports and harbours are also listed as priorities for development, with a dedicated Communities Fund set to underpin regeneration work in coastal areas.

Significantly, marine transport and “boat-based tourism” are included in a “pipeline of projects” in line for future investment.

It comes amid continuing concern over the quality of lifeline ferry services to and from the islands.

Stressing that the approach to improving life for residents and firms would be collaborative, Ms Bryan added: “We are looking forward to working with communities and businesses to deliver positive change for Scotland.”

However, support for the Crown Estate’s latest blueprint has not been universal.

Describing it as a “mixed bag”, Richard Dixon, Director of Friends of the Earth Scotland, criticised planned moves to assist fish farming.

And he warned that “encouraging” carbon capture and storage technology would make it harder to wean the country off fossil fuels as it pursues its target of achieving net zero emissions by 2045.

He said: “On the one hand the commitment to help deliver a major expansion in offshore windfarms is very welcome news in the fight against climate change and the pledge to involve coastal communities in decisions which affect them is very significant.

“On the other hand, the enthusiasm for expanding the fish farming industry is disappointing, particularly as this industry continues to struggle to meet pollution standards.

“Support for wave and tidal power is also welcome but encouraging Carbon Capture and Storage could lock us into using oil and gas for much longer than the planet can stand.”

Fish farm leaders rejected criticism of their industry’s pollution record and said expansion would provide significant benefits.

“Salmon farming is a vitally important contributor to rural and coastal Scotland, especially in remote areas,” said Hamish Macdonell, Director of Strategic Engagement for the Scottish Salmon Producers Organisation (SSPO).

“While the development of new salmon farms benefits both rural and national economies, no new farm is developed without rigorous scientific impact analysis of the proposed site, local consultations and the approval of regulators and the local authorities.

“With that clear support, the development of Scottish salmon farming should be welcomed.” Crown Estate Scotland manages 37,000 hectares of rural land, including agricultural tenancies, properties and forestry on four rural estates - Glenlivet, Fochabers, Applegirth and Whitehill.

It is responsible for rights to fish wild salmon and sea trout in river and coastal areas, as well as naturallyoccurring gold and silver across most of Scotland.

Just under half the country’s foreshore, including 5,800 moorings and some ports and harbours, are in its control.

Leasing of virtually all seabed out to 12 nautical miles also comes under its powers, along with rights to offshore renewable energy and carbon dioxide storage out to 200 nautical miles.

The arrangement covers some 750 fish farming sites, and agreements with cable and pipeline operators.

All of CES’ revenue profit is paid to the Scottish Government for public spending. In the first two years since being established in 2017, it has returned over £20m to ministers.