Google’s mystery barge in Portland Harbor is well behaved compared to its bad-barge counterpart in San Francisco.

The agency that oversees development in San Francisco Bay has begun a formal investigation into the construction of the barge on an island in the bay, officials told Reuters on Wednesday.

The purpose of the probe, which the San Francisco Bay Conservation and Development Commission began in the past week, is to examine what permits are needed to outfit the structure and whether the owners of the Treasure Island pier, where the vessel is moored, have the proper permits.

Google is in the process of making changes to the barge’s design as requested by the Coast Guard, which has inspected the barge as part of its standard practice of examining newly built vessels to ensure that safety, security and environmental protection regulations are met.

Construction of the barge in San Francisco is proceeding well ahead of the Portland barge, which was assembled in New London, Conn., and hauled by tugboat into Portland Harbor on Oct. 10. The barge is moored at the Rickers Wharf Marine Facility, where Cianbro Corp. is scheduled to do a significant amount of interior work. To date, very little, if any, work has been done.

The Portland barge is not under scrutiny by officials because the Rickers Wharf Marine Facility is located in a land-use zone that allows for marine construction, according to officials with Portland’s Planning and Urban Development Department.

The two barges, which are made of steel shipping containers stacked four stories high, stirred intense speculation about their purpose when their connection to Google was first reported two months ago. The San Francisco barge is just 32 miles away from Google’s headquarters in Mountain View, Calif.

The two barges are owned by a company affiliated with Google called By and Large.

Google has remained secretive about the barge, and Cianbro officials say they have been told to keep mum about the project.

In documents it submitted to the San Francisco Port Authority, By and Large described the floating structure as “interactive spaces” and “temporary technology exhibit space.”

However, according to internal budget documents for Turner Construction Co., which is working on the barge in San Francisco, three barges are proposed, and each will support a floating store for launching Google Glass, a wearable computer built into glasses-like frames that is now in development.

The barges are expected to be moored at docks in San Francisco, New York City and Los Angeles in a project that will cost $35 million, according to the documents.

Google could not immediately be reached for comment Thursday.

Tom Bell can be contacted at 791-6369 or:

[email protected]

Twitter: TomBellPortland