One of the fixtures of Boston Harbor are the World War II-era amphibious landing vehicles, affectionately known as “ducks.” Those tourist-carrying ducks are going to have more than water rolling off their backs… they’ll have carbon emissions rolling away as they switch to cleaner burning biodiesel.

This story in the Boston Herald says Boston Duck Tours has been wanting to make the change for some time, and now it is making the green fuel part of its package:

The $300,000 vehicles initially will run on a B5 biodiesel fuel blend that’s 5 percent vegetable oil, according to director of vehicle maintenance Tony Cerulle. The vehicles’ manufacturer will only cover the one-year warranty for their diesel engines if that mix is used.

“We’ll probably go up to 40 percent or 50 percent (vegetable oil) after that,” Cerulle said. “But the real savings is if you were to run straight vegetable oil or blend your own biodiesel.”

Five “ducks” will run on the green fuel.