Marine surveys are taking place in Morecambe Bay ahead of a major project to connect a new electricity pipeline from Barrow to Heysham.
The National Grid is digging boreholes from two drill rigs off the coast at Heysham up to 100 metres below the sea bed.
These are the first major marine surveys by the National Grid in Morecambe Bay since 1968.
They are being carried out ahead of a public consultation on the North West Coast Connections project.
The work is likely to continue for another four weeks.
Results could influence the route for an under-bay tunnel carrying electrical cables.
The surveys will also provide a detailed insight into the geological make-up of the bay.
The National Grid is exploring 23 sites in total.
Seven boreholes will reach a depth of 100 metres below the sea bed, while the other 16 will need to be 60 metres deep.
The boreholes are needed to show National Grid where different geological layers begin and end under the surface of Morecambe Bay.
During the consultation, exhibitions will be held along the project route. Members of the public will be invited to give feedback on proposals.
Robert Powell, project manager, said: “Our proposal to build a tunnel across Morecambe Bay is one we are very excited about.
“We are hopeful that these surveys will give us invaluable information about the bay should plans for the tunnel go ahead.
“We will be asking for people’s views on the tunnel and other elements of our project during a public consultation later this year and we encourage people to take part and let us know their views.”
People can register their details on the North West Coast Connections project website now to ensure they get regular updates on the project and details of the consultation:
The website is www.northwestcoastconnections.com .