A proposed public-private high-speed ferry that would link MacDill Air Force Base to downtown Tampa and St. Petersburg got a big boost Monday with the news of a $4.8 million federal grant for the project.

U.S. Rep. Kathy Castor (D-Tampa) announced the U.S. Department of Transportation grant to Hillsborough Area Regional Transit, the agency that would operate the ferry, which would also run to Gibsonton in southern Hillsborough.

"Tampa Bay's long-term economic future will significantly benefit if we develop options for people to travel to work and home," Castor said. "Investing in our infrastructure is key to growing jobs in our community and remaining competitive."

The overall price tag for the ferry is $17 million, so Monday's announcement means Hillsborough County would still have to chip in upwards of $12 million to get the service up and running. In February, county commissioners approved spending up to $125,000 to study the ferry's feasibility.

Former county commissioner Ed Turanchik, a longtime advocate of public transit, is representing the private companies that would partner with Hillsborough. Turanchik has pitched the ferry primarily as a way to get MacDill employees who live in southern Hillsborough to work during the week, with the Tampa and St. Petersburg routes added on nights and weekends.

©2014 Tampa Bay Times (St. Petersburg, Fla.)