Story highlights San Francisco barge structure confirmed as showcase for Google Glass, sources say

CNN affiliate KPIX reports structure will be high-end showrooms for Glass eyewear

Three similar barges, including one in Maine, have been spotted

Whatever is on the barge has been shrouded in mystery

The mystery barge in San Francisco Bay is indeed a Google project , and houses a fancy, floating showroom for Google Glass and other products, a CNN affiliate is reporting.

According to KPIX-TV in San Francisco , the barge structure will become one of a small fleet of luxury event spaces, complete with a party deck for invitation-only visitors.

The station cited "multiple sources" including at least one who has been aboard the barge, and said it was dreamed up at Google X, the company's secret facility where engineers have cooked up projects like Google Glass and a self-driving car.

The facility is constructed from interchangeable shipping containers and is designed to be disassembled and transported via barge or train to other locations, a source said.

At least two other similar barges, including one in the Portland, Maine , harbor, also have been spotted since the "mystery barge" -- docked at a pier on Treasure Island, just east of San Francisco -- first made headlines earlier this week. All of them are marked by the letters "BAL" and four numbers. An unnamed tenant that moved into a hangar on Treasure Island on August 1 goes by the handle, "By And Large" -- possibly a playful reference to the corporation in the Pixar movie "Wall-E."

The mystery barge sits in Clipper Cove off Treasure Island, just east of San Francisco.

The fancy barges will be an effort by Google to upstage rival Apple's stylized retail stores, a source said.

In a statement, the U.S. Coast Guard confirmed it is working with the barges' owners to make sure the floating structures have the proper permits and permissions to operate in the bay. But it didn't say much else.

"Regardless of the company or entity involved, the Coast Guard has an obligation to protect sensitive proprietary information, as a company's competitive posture and business interests depend on it," said the branch of the U.S. military in the brief statement.

Google Glass, worn like regular glasses, has a high-resolution display and lets wearers use voice commands to shoot photos or videos and access features like e-mail, text messaging, Google Maps, Google search and a handful of other apps.

It is currently being tested by about 10,000 "Explorers," who paid $1,500 for the glasses. That program is being expanded. This week, Google announced current testers may invite up to three friends, as well as a planned rollout of a new version of Google Glass.

If the reports about the barges are true, it may take some time before the project is officially confirmed.

Google has declined to comment on the reports. And a shroud of secrecy has cloaked the entire proceedings.

A sign outside the By And Large hangar on Treasure Island has a sign saying that all visitors must hand over their cellphones, cameras, and other recording devices.

San Francisco Mayor Ed Lee is also among those in the dark.

"They've kept a secret from me as well," he told KPIX.