a deep dive into what that means for the future and why there are still some concerns about their impact on the environment. >> reporter: for more than a century ferry boats have moved people around san francisco bay. powered mostly by diesel, a planet-warming fossil fuel. so this is the boat of the future? but now there is a sea change coming. >> down the hatch. >> reporter: down the hatch. this is the first passenger ferry in the world. >> so these are the fuel cells. >> reporter: powered entirely by hydrogen fuel cells. >> instead of big diesel engines spinning things to make power, just happens in the fuel cells. jeff sokolik is with all american marine in bellingham, washington, it built a 75 passenger catamaran that will