SeaWorld has denied the charges, but park attendance dropped 12% last year to about 3.8 million, according to one estimate, while shares of SeaWorld Entertainment, the parent company of the park, have plunged. Opponents accused SeaWorld of being motivated by a drive for bigger profits.



"How can anyone who has the whale's health in mind say this is a bad idea?" Nollens said of the project.



But Ingrid Visser, head of the Orca Research Trust in New Zealand, blasted the project, saying whales in the wild swim an average distance of 138 miles per day and dive to depths of about 600 feet. The new tank will have a surface area of 1.5 acres and a depth of 50 feet.



"These new tanks do not meet these basic requirements," she said. "No facility ever will."



She echoed the sentiments of other opponents who say the orcas should be released to a seaside pen or sanctuary.



"If SeaWorld truly cared about their animals they would move them to a seaside sanctuary," said Anderson, wearing a T-shirt emblazoned with "SeaWorld Kills."



Eight of the 11 orcas at SeaWorld were born in captivity, and the other three have spent many years in the park. SeaWorld officials say the whales can no longer thrive in the wild.



It would not be the first time the Coastal Commission has imposed conditions on a project to protect captive animals. In 2002, the state panel, deciding on a roller coaster project at SeaWorld, required that the park shield its whales and dolphins from the noise generated by the attraction.



Other conditions proposed by the commission staff call for SeaWorld to reduce the effects of noise, traffic and runoff caused by the project.