The 14,000km subsea cable connecting Australia and New Zealand to Hawaii and the West Coast of the United States has finally commenced construction, almost three years after first being announced.

The cable will be jointly constructed by Hawaiki Submarine Cable, based in Auckland, and TE SubCom, a company from Eatontown, New Jersey. According to the two companies, they began route planning in June last year, and expect completion of the project by mid-2018.

The cable, which has the option to extend to several South Pacific islands along the route via TE SubCom's optical add/drop multiplexing (OADM) nodes, will have a capacity of over 30 Terabits per second (Tbps). The cable makes use of TE SubCom's C100U+ Submarine Line Terminating Equipment (SLTE).

The cable was reported in 2013 to cost $350 million to construct, and is privately owned and "carrier neutral". It was co-developed by Sir Eion Edgar, a prominent New Zealand businessman whose company provided "substantial" investment for the cable in July last year, and Remi Galasso, the CEO of Hawaiki.

"This is the beginning of a new era for New Zealand and the Pacific Islands in terms of international connectivity," Edgar said.

"We are excited to be at the forefront of this very significant infrastructure investment."

Alongside Edgar and Galasso, Malcolm Dick, co-founder of New Zealand's third-largest telco Slingshot, also provided funding for the subsea cable.

"The lack of an alternative cable system connecting Australia, New Zealand, and the US has long been a concern of mine, so I am delighted to be part of this project," said Dick.

"Having built telco businesses in both Australia and New Zealand in the past, I am very aware of the need to provide competition by being independent of the incumbent operators. This increased level of competition and capacity should make data caps a thing of the past."

Research and Education Advanced Network New Zealand (REANNZ) welcomed the news of the cable's construction, with chairman Jim Donovan saying a second subsea cable would provide "much-needed new capacity and diversity of supply" for connectivity in New Zealand.

REANNZ was a founding customer of the project, with the Hawaiki cable to connect directly to its national network and help it deliver high-speed internet to REANNZ members across the country. With a growth in traffic of 84 percent experienced across REANNZ's network during 2014-15, CEO Nicole Ferguson said the cable is necessary.

"The Hawaiki cable project provides REANNZ with the ability to not only meet today's research and education demand, but to support the needs of the next generation of research, education, and innovation," Ferguson said.

"New Zealand researchers and educators require greater access to global content, resources, and tools to remain competitive and successful in their respective fields. This makes high-performance international connectivity crucial, to ensure the ongoing success of our members."

Back in August 2013, Australian internet service provider TPG signed on to pay between AU$10 million and AU$14 million in capex over three years for 3Tbps of capacity on the Hawaiki cable -- to which it can also add the 3Tbps of capacity that iiNet signed a multimillion-dollar agreement to purchase in October 2013, thanks to its AU$1.5 billion takeover of iiNet.

TPG's own Sydney-Guam submarine cable experienced a month-long outage in February, with TPG customers also affected by the current Basslink Interconnector outage. The Trans-Tasman cable has been down since December, and will not restore services until at least mid June.

Also constructing a high-capacity subsea cable are Telstra, Singtel, and SubPartners, which on Thursday announced entering a memorandum of understanding to build a high-capacity Perth to Singapore cable.

The cable, named APX-West, will be 4,500km long, with two fibre pairs providing a minimum of 10 Terabits per second capacity each pair and two-way data transmission. It will replace the slower-speed SEA-ME-WE 3 (SMW3) cable, which currently carries data traffic between the two countries.

It took APX-West a similar three years to get off the ground; Telstra had initially signed an MOU with SubPartners for capacity on the subsea cable back in March 2013.

Like the Hawaiki cable, APX-West is now privately owned. The companies will begin constructing it at the end of July, with completion expected during 2018.

Telstra's decision to sign on to help construct APX-West is timely after the telco's own Australia-Singapore subsea cable experienced an outage in October last year.