By Alexei Oreskovic SAN FRANCISCO (Reuters) – Able-bodied seamen, decorative sails meant to evoke fish fins and dozens of security cameras will eventually make up the on-board complement of a mysterious four-story barge being built by Internet company Google Inc. The barge is actually a technology exhibition space, that Google will move between several piers in the San Francisco Bay area and other West coast locations over the next two years, according to a 36-page information packet submitted in August to the Port of San Francisco. an experience unlike any other that celebrates community, local organizations and the history of San Francisco, reads the document, which lists the project as being spearheaded by By and Large LLC. The floating structure built of stacked shipping containers, and a twin vessel in Portland, Maine, have stirred intense speculation about their purpose ever since reports of their existence surfaced last month. Google has gone to great lengths to keep the details of the barges secret, requiring at least one U.S. Coast Guard employee to sign a non-disclosure agreement.