Anyone with a boat creates air pollution that eventually comes down as rain & into bodies of water. With FAE some of the pollution (esp. soot) is going to get scrubbed out of the exhaust so the remainder going in to the air is cleaner. Soot contributes to global warming so scrubbing the soot from the exhaust may help to reduce a global warming pollutant. As far as damaging the water, FAE does nothing different with the exhaust than outboard & stern drive boats have been doing for decades.
Anyone with a boat creates air pollution that eventually comes down as rain & into bodies of water. With FAE some of the pollution (esp. soot) is going to get scrubbed out of the exhaust so the remainder going in to the air is cleaner. Soot contributes to global warming so scrubbing the soot from the exhaust may help to reduce a global warming pollutant. As far as damaging the water, FAE does nothing different with the exhaust than outboard & stern drive boats have been doing for decades.
What damage are you talking about?