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