They are basically bandwidth hogs.”

–Alan Mauldin, research director with Washington-based research firm TeleGeography, comments on Google’s capacity requirements.

If your corporate mission is to organize the world’s ever-increasing mass of digital information and make it universally accessible and useful, sooner or later the telecom costs and peering fees associated with the transmission of that information are going to get, you know, quite large. So large, in fact, that it may make sense to build out your own network.

Which is why for the past few years, we’ve been hearing rumblings about Google (GOOG) leasing hundreds of thousands of square feet of carrier hotel space, buying up dark fiber and mulling the purchase of hundreds of millions of dollars in DWDM and Ethernet-based telecom equipment.

It’s clear that Google has a big appetite for network capacity, but apparently it’s quite a bit larger than previously thought–undersea-cable large. This morning Google revealed that it had joined a six-company consortium to build out a trans-Pacific multi-terabit undersea cable. The project is called Unity and is scheduled for service launch in 2010.

“As more and more people conduct online searches and interact with applications like Gmail, Google Earth and YouTube, we’ve had to think outside the box to create a more scalable, affordable and easy-to-manage network that meets our users’ needs worldwide,” Google’s Manager of Network Acquisitions Francois Sterin wrote in a post to the company blog. “One of the biggest challenges we face is staying ahead of our broadband capacity needs, especially across Asia. One of the ways we are addressing this is by working with five other international companies to create a consortium. Collectively we just signed an agreement to build a new high-bandwidth subsea cable system linking the U.S. and Japan (more detail in the press release). This cable system, named Unity, will address increasing broadband demand by providing more capacity to sustain the unprecedented growth in data and Internet traffic between Asia and the U.S. Our participation in building Unity ultimately helps provide our users with faster and more reliable connectivity.”

And Google itself with an easy means of becoming a full-fledged network operator, if it so chooses, right? Sterin says no. “If you’re wondering whether we’re going into the undersea cable business, the answer is no,” he wrote. “We’re not competing with telecom providers, but the volume of data we need to move around the world has grown to the point where in some cases we’ve exceeded the ability traditional players can offer.”

Google declined to comment on the plan and did not confirm that it has hired the sort of submarine cable specialists that might work on it. “It should come as no surprise that Google is looking for qualified people to help secure additional network capacity,” said spokesman Barry Schnitt. “In some parts of the world, these people will work with submarine cables because there is a lot of ocean out there. … Additional infrastructure for the Internet is good for users, and there are a number of proposals to add a Pacific submarine cable. We’re not commenting on any of these plans.”