Every now and then people stop to look at the concealed barge holding white storage containers wrapped in construction mesh. You wonder what the antennas are for -- if that's what they even are.
There are fences all around it and security guards on the pier, but that doesn't stop ideas from floating around.
"I think it's an underwater water system that Google has been working on to who ocean bottoms and things like that, otherwise why would they build something on a barge," onlooker Jean Mondeau said.
Patrick O'Hara is a contractor on Treasure Island whose been watching the operation for more than a year now.
"Bringing containers in, filling them up with stuff, cutting them up, painting them white, shipping them off, he said. "I have not seen what's inside, some have electronic gear, some are empty."
Google has a patent application for a floating platform-mounted computer data center. So a few tech experts think that's what they are building.
There's a second barge now in Portland, Maine. It will be completed after the one in the Bay Area is finished.
Google has met twice with the San Francisco Bay Conservation and Development Commission, the agency which hands out the permits to use the bay.
"What we think it might be is a way and what Google has described to us as a way for the Bay Area to learn about technology," spokesperson Larry Goldzband said. "That's as much as we know."
All we know now is that Google has promised to release information once the project is completed. With construction still ongoing, that may be awhile.