New measures to encourage electricity suppliers to use wave and tidal power have been unveiled by the Scottish Executive.
Marine energy could help meet Scotland's electricity needs
Enterprise Minister Nicol Stephen said renewable wave and tidal energy could provide up to 10% of Scotland's electricity production.
About 7,000 jobs could be created by such projects.
Mr Stephen said the changes he was making would "unlock Scotland's marine powerhouse".
The minister told Offshore Europe delegates in Aberdeen that he would take action to award additional Renewable Obligation Certificates (ROCs) to wave and tidal output, with the aim of putting Scotland at the global forefront of marine energy.
The executive's target is that 18% of electricity generated in Scotland should come from renewable sources by 2010, rising to 40% by 2020.
"Tens of millions of pounds of support will be available - with the potential for hundreds of millions to be invested in new wind and wave projects around Scotland's shores," Mr Stephen said.
"Our aim is to generate up to 10% of Scotland's electricity from the sea around us. That is equivalent to completely replacing one of Scotland's huge fossil fuelled power stations.
"Already we have the technology to become the global capital for the development and generation of energy from world's oceans. Marine power could become one of our biggest industries of the future.
"We have already done much to support the sector, particularly at the world class testing centre on Orkney," he said.
"Yet to date, in contrast to wind power, we have seen no significant commercial projects for wave or tidal power in Scotland. That has to change.
"To deliver, we need to do more. Development on a large scale will drive down costs and make it possible for these devices to power the engine of a sustainable Scotland."
He said the plans would bridge the funding gap and mean that while wind schemes would continue to get support, wave and tidal projects would get an even greater boost.
A group of industry experts said the potential exists to install over one gigawatt of wave and tidal capacity in Scottish waters - about one-tenth of the country's total electricity production.
"These developments will not only boost our renewable energy output, but we can expect to see many new jobs created in the design, manufacture, installation and export of these technologies," Mr Stephen added.
"The opportunity for Scottish business is truly worldwide. If we can establish a lead in marine energy, the global potential for our companies is massive.
"Wave and tidal energy is one of Scotland's biggest opportunities. We must take action today to produce the clean energy of tomorrow."
Green energy group, Scottish Renewables, welcomed the measures.
Chief Executive Maf Smith said: "This major announcement shows that the executive is not going to stand idly by and watch our early lead in marine industry drift away and their leadership is very welcome.
"Wave and tidal energy has vast potential and if properly supported could join hydro and onshore wind projects as a means of delivering our future electricity needs, tackling climate change and bringing skilled employment to Scotland."
Scotland is said to have "vast potential" to exploit wave energy
Duncan McLaren, chief executive of Friends of the Earth Scotland, said: "The UK's coastline has huge potential for wave and tidal power, which could help reduce our reliance on polluting fossil fuel and hazardous nuclear plants.
"We know the public backs renewables and many would jump at the chance to have their home powered by a combination of electricity generated from the waves and tides."
The Scottish National Party's energy spokesman Richard Lochhead said: "At long last ministers have woken up to the power of Scotland's seas and the potential for marine renewables.
"For decades, the marine renewables community have been crying out for action and now we find ourselves playing catch-up with other countries when we should have been leading the pack."
Shiona Baird, the Green Party's enterprise spokeswoman, said: "It remains to be seen whether this will truly capture the market potential for Scotland but it is a step in the right direction."