Documents submitted to the Port of San Francisco show that the barge's creators have big plans for the bulky box now docked at Treasure Island. By and Large LLC, which submitted the barge documents, refers to the vessel as a "studio" and "temporary technology exhibit space." Whatever it is, the barge's backers expect it to draw 1,000 visitors a day as it sails from spot to spot around San Francisco Bay. Among the envisioned mooring sites are Piers 30-32 and other San Francisco docks, Fort Mason, Angel Island, Redwood City and Rosie the Riveter/World War II Home Front National Historical Park in Richmond. Eventually, the barge would sail off to San Diego and other West Coast ports. San Francisco Port spokeswoman Renee Dunn Martin said the pitch, which By and Large submitted in September, was "part of a preliminary proposal. "The artistic structure combines innovative architecture with a bit of nautical whimsy," the proposal says, "creating a surprising environment that inspires conversation, community and 'a-ha' moments."