Commissioner Greg Cox, who also is a San Diego County supervisor, noted "near-unanimous" support of the project by public speakers, who represented the region's business community, tourism industry and labor organizations.

He and other commissioners noted their task was not to weigh the project's economic benefits, but rather the impact on views and access of the downtown waterfront. Coastal Commission staffers have recommended denying the $520 million project because it may limit access to San Diego Bay, reduce the waterfront views and eliminate a park built to mitigate construction of the Hilton San Diego Bayfront.

Construction of a pedestrian bridge from the Gaslamp Quarter over Harbor Drive to the center would resolve their access concerns, but project backers said they can't afford it.

Project boosters say the addition of 740,000 square feet to the building would give it the largest amount of contiguous floor space on the West Coast, prompting an addition of 25 major convention and trade shows annually -- equivalent to a year's worth of business currently. Interim Mayor Todd Gloria also said the expanded center would create 7,000 permanent jobs and generate an annual economic impact of $700 million in San Diego. City coffers would expand by about $13.5 million in annual tax revenues, he said.