The long-anticipated east coast rail project is set to connect Brisbane, Sydney, Canberra, Melbourne and regional communities in between.

Drilling has begun on the NSW Central Coast to determine the route of the first stage of the project, to connect Newcastle to Sydney.

Two drill rigs were set up on Monday on the Hawkesbury River and at Brisbane Water in Gosford, with plans to drill six boreholes up to a depth of 140 metres.

They will collect rock and sediment samples to inform the design and depth of potential rail tunnels.

About 27 boreholes will be dug across the Sydney to Newcastle region, backed by the federal government's High-Speed Rail Authority.

The government has committed $500 million for the planning and corridor protection of the first stage of the project.

The long-term infrastructure project would ultimately allow passengers to travel between major cities and significant regional cities at more than 250km/h.

With AAP.