The strong tides and choppy waters around Scotland's coasts hold an estimated 25% of Europe's potential tidal energy and 10% of available wave power.

So, as well as a being the possible world leader in wind power, Scotland is the natural home of marine energy development. Several of the companies leading the push to harness the power of the sea on a commercial basis appear to agree.

The Scottish Government announced yesterday that, to date, two tidal energy projects and two wave power devices have joined the fight to win the Saltire Prize: the £10 million award that will go to the one that produces the most electricity over two years (over the minimum hurdle of 100 gigawatt hours). Other firms could join later, as more than 150 companies from 31 countries have registered an interest.

It is a clever idea. The lure of a substantial cash prize is intended to speed up the pace of development and stimulate innovation, raising the twin prospects of powering Scotland from renewables and improving energy security.

However, as none of the £10m will be distributed until 2017, it is no substitute for state support towards development and initial commercial deployment of wave and tidal power, the two most capital intensive forms of renewable energy. There are many challenges to be overcome, including improving power conversion and deploying and managing these devices in some of the harshest marine environments in the world. Yesterday Scottish Green MSP Patrick Harvie criticised the SNP Government for talking up the potential of ocean energy while failing to offer adequate day-to-day support.

The Government's reply is that it is doing what it can through the UK Renewable Obligation Certificates (ROCs) scheme and its own Waters (Wave and Tidal Energy: Research Development and Demonstration Support) fund. Is it enough to maintain Scotland's lead?

In reality, Alex Salmond continues to hedge his bets on renewables by pursuing a dual high-carbon, low-carbon strategy. So he claims that Scotland can lead the world in reducing its carbon footprint, while approving new coal and waste-to-power incinerators. Meanwhile, support for marine energy remains modest and piecemeal.

Scotland should have learned its lesson from the fate of the wind-power market, where a lack of investment meant the country failed to keep pace with its competitors, handing the lead to Germany and Denmark.

Commercial-scale ocean energy is a holy grail that in the 1970s was no more than a gleam in the eye of Professor Stephen Salter. The Edinburgh University engineer, who led the team that designed the "Salter's Duck" wave energy machine, was once dismissed as a crank. Now he is hailed as the founding father of a technology with the potential substantially to reduce Scotland's carbon emissions.

It is an industry that could one day generate many gigawatts and thousands of Scottish jobs. Scotland's early lead must be exploited to full advantage.