It is freezing cold and the fog is slowly lifting over Helsinki.
There are dozens of ships anchored in the harbour.
Nord Stream, a consortium led by Russia's Gazprom which is building a new controversial pipeline, has several vessels moored at the quayside.
For months, crew members have been out at sea, carrying out surveys of the seabed in order to ensure the route of the planned pipeline is safe.
It is a huge technical and logistical challenge. The pipeline is about 1,200 kilometres (750 miles) long and it will run from Vyborg, in Russia, under the Baltic Sea, to Greifswald, in northern Germany.
Once construction is completed at the end of 2010, the pipeline will supply Russian natural gas to customers all over Europe. The long-term goal is to supply up to 55 billion cubic metres of gas each year.
However, there is a hefty price tag - the pipeline is expected to cost at least 5bn euros ($7.4bn, Â£3.7bn), but due to delays, the cost could rise.
At the same time, there is growing opposition to the pipeline from governments and private environmental groups.
There is a perception that the pipeline was a project drawn up between Russia's state energy company Gazprom and Germany, and other countries claim they were not consulted.
Poland and the Baltic states say they feel they have been bypassed, claiming they will also lose transit fees.
The new Polish Prime Minister, Donald Tusk, says he will continue to push for the planned Russian-German gas pipeline to pass through Poland, rather than under the Baltic Sea.
Mr Tusk says a Polish route would be cheaper and he wants to hammer home the need to diversify energy supplies and ensure independence from Russia.
Many people in Finland also have deep reservations about the new pipeline. Finland's environmental agency wants the pipeline to be moved further south.
"We are generally in favour of completing the pipeline project in order to have an alternative source of supply," says Jorma Korhonen, the director general of the Finnish Department for External Relations.
"But environmental factors have to be taken into account. We are concerned about the impact on the environment."
Environmental group Greenpeace has also criticised the project.
"This pipeline involves huge risks. We do not know what will happen when the seabed is disturbed," says Juha Aromaa, a spokesman for Greenpeace.
"The Baltic Sea is polluted and some of the poisonous substances on the seabed could re-surface. The pipeline also passes through several places which have been designated marine conservation areas," he adds.
In an effort to allay concerns, Nord Stream is conducting an environmental impact study using state-of-the-art technology.
"The survey operations for Nord Stream involve acoustic and intervention surveys including side-scans, and remotely operated vehicles, using a gradiometer," says Bob Pirie, Nord Stream's offshore representative for survey operations.
"We are pushing the boundaries of surveys along such a long survey corridor."
The Gulf of Finland was heavily mined, and along with chemicals, were dumped in the sea during World War II.
Engineers working on the project have been combing every inch of the seabed to make sure there are no hidden dangers.
They have divided the 1,200km-long corridor into different blocks and have accumulated vast amounts of data. All the images filmed on the seabed are stored and analysed.
So far, Nord Stream engineers say the majority of objects that they have found were boulders, ship-wrecks and even a few shopping trolleys and washing machines.
But did they find any mines?
"We have found several munitions-related items," says Simon Bonnell, the senior project engineer at Nord Stream.
"From information available in the public domain, it is clear where the mine curtains were laid and so it's a quantifiable issue and we are identifying where the mines may be a potential risk to the pipeline.
"If we find a mine, we inform the national authority, and we would re-route the pipeline," he explains, adding that the real challenge is the length of the pipeline, the shallow nature of the Baltic Sea and the irregular seabed.
Nord Stream officials are keen to point out that the pipeline project is not just a bilateral deal between Germany and Russia.
Nord Stream is made up of Gazprom, which holds a majority 51% stake, German energy companies E.ON Ruhrgas and BASF/Wintershall, which share a 40% stake, and Dutch energy firm, Gasunie, which recently acquired a 9% stake.
"The project is very international," says Sebastian Sass, a permitting manager at Nord Stream.
Mr Sass continues that it is mutually beneficial for the companies and nations involved in the pipeline project, and adds that the pipeline has been granted "priority project" status by the European Union.
"The demand for natural gas in Europe is increasing. Domestic resources are depleting," he says.
"We will now have long contracts of around 20 years. Our shareholders are committed. The Russians are dependent on exporting gas, and the EU is dependent on imports, so there is mutual dependency," Mr Sass explains.
So why did Nord Stream decide to build an offshore pipeline?
Officials claim there are strong commercial and environmental reasons.
"If we build an overland pipeline, there are villages, forests and lakes which we have to deal with," says Mr Sass.
"We can transport more gas under higher pressure with an underwater pipeline. We don't need midway compression, it's cheaper and it's safer."
Nord Stream is due to finish the fourth stage of its survey operations in January 2008.
The consortium is planning to publish its Environmental Impact Assessment Report in spring 2008, as required by United Nations environmental legislation.
Then comes the difficult task of obtaining construction permits.
It is clear that Nord Stream still faces an uphill battle.
- 183 Environment
- 190 Natural Resources