The company building part of a huge underwater digital cable network that will come within 170 kilometres of Tasmania has warned the State Government costs will go up the longer it delays investing in the project.

The Government says it is seriously considering a substantial investment in the project, but is yet to make any solid commitment.

The cables are part of the network which is replacing satellites as the preferred means of global communication.

The developer SubPartners says it has given Australia's southern states the opportunity to connect for around $20 million.

The cable, to be known as the Asia Pacific Express Central (APX Central), would stretch from Perth, which is already connected to Singapore via the network, arc along the southern border around Tasmania and end up in Sydney.

Cables connection cost will go up: SubParnters

SubPartners commercial director Carlos Trujillo said while the major cable was already funded, states could benefit from increased connection.

"It makes economic sense to try to provide connectivity to the different states; we're putting branching units off South Australia... Victoria and Tasmania," he said.

He said that if the states did not connect now, they could do so in the future, albeit at a significantly higher cost.

"We're going to build the cable no matter what. We're future proofing it by putting the branching units in," Mr Trujillo said.

"If the Tasmanian, Victorian or South Australian Governments decide to participate before we start construction, they benefit... but to bring a ship out for a second time, obviously there's significant costs associated to that."

Tasmanian IT experts urge Government to act

Global submarine cable network Consists of about 900,000 kilometres of cable

Consists of about 900,000 kilometres of cable There are 285 separate cables

There are 285 separate cables The first were laid in the 1850s to carry telegraphy data

The first were laid in the 1850s to carry telegraphy data The longest cable stretches 39,000km

The longest cable stretches 39,000km The network now carries almost 95 per cent of the world's internet traffic

Information Technology Minister Michael Ferguson said the Government was "actively exploring the proposal together with stakeholders".

Tasmanian is currently reliant on two cables, both of which come from the Australian mainland, and the Minister conceded a third was necessary, "to put Tasmania on the map as a prime data centre location we need three."

Tasmanian IT experts were urging legislators not to sit on their hands.

"This is one of the most significant infrastructure projects in recent history in Tasmania," Dean Winter from TAS ICT said

"It opens up a whole range of new opportunities for Tasmanian businesses and not just in the ICT space but right across the broader economy."

Submarine cables around the world, June 2014 (Supplied: TeleGeography www.submarinecablemap.com)

The world wide web is becoming increasingly reliant on its underwater network, with almost 95 per cent of information on the internet carried by these cables along the sea floor.

'Ends of the earth' getting wired

US based company TeleGeography, which has mapped the underwater network for several years, reported the number of cables had almost doubled in the last two years.

"Satellites don't play a major role anymore in how the world connects so it's largely all underwater cables linking the major continents," said the company's research Director, Alan Mauldin.

"You're seeing new cables being built to more remote places: Tonga has a cable, Vanuatu has a cable.

"Really, the ends of the earth are being wired with undersea cables."

The cables do not only carry the internet.

Telecommunications companies have been laying cables along the ocean bed since the mid 1800s.

Today's cables are around 10 centimetres thick and are made of optical fibre, to maximise the content they can carry.