Tampa Electric Co. wants to get people even closer to the manatees that gather in the warm waters near its Big Bend Power Station in Apollo Beach.The company has proposed an expansion of the long dock stretching westward from its Manatee Viewing Center, which draws hundreds of manatees and 600,000 visitors each year.Plans submitted to Port Tampa Bay show a 152-foot T-shaped pier extending north from the larger dock, closer to the plant and its discharge waters. The 2,280-square-foot elevated dock would stretch more than 40 percent of the way across the canal, requiring a variance from Port Tampa Bay.The pier would not impact waterway traffic, as the canal is closed to public boating for both plant security and manatee safety measures. But it is a state and federal manatee sanctuary, and thus still requires approval from several agencies, including the Department of Environmental Protection and U.S. Army Corps of Engineers.The port’s board approved a work permit to execute the plan on Tuesday. Tampa Electric spokesperson Cherie Jacobs said the goal is to open the pier extension by this fall.