Some new clues are emerging around a mysterious barge floating in San Francisco Bay off Treasure Island.
Several reports speculate the barge is home to a floating data center that may be owned by Google. Google sources have said repeatedly they have no comment, but now there is independent confirmation.
"We can confirm that Google is involved or associated with the barge but there is a nondisclosure agreement in effect; the Coast Guard is unable to discuss or divulge any further details at this time," said Petty Officer 1st Class Thomas McKenzie, a Coast Guard spokesman.
As CNET first reported, Google does have a patent for a water-based data center that can be cooled by the flow of sea water.
CNBC spoke with several data center experts who said the idea could work.
That's because it it mobile and could be deployed off any coast around the world. The experts spoke on condition of anonymity.
And while most of the attention has been on the hulking structure floating in San Francisco Bay, the plot of the mystery is thickening.
Another barge that looks eerily similar, and is reported to be registered to the same holding company as the one in San Francisco, appeared off Portland, Maine, just last week. There is no independent confirmation the two barges are related.
As we've learned new developments about the story, we have repeatedly reached out to Google. The company continues to provide "no comment on the story."
While Google is known for its secretiveness, the tide of information about these mystery barges/floating data centers is rising.
—By Mark Berniker and Josh Lipton of CNBC's SiliconValley/SF Bureau. Follow Berniker on Twitter @markberniker and Lipton @CNBCJosh.