And likely the equivalent 10% gain in environmental efficiency. On the curve displayed on the website linked there are places where the efficiency if far more

And likely the equivalent 10% gain in environmental efficiency. On the curve displayed on the website linked there are places where the efficiency if far more than 10%. At 3000 rpm the efficiency gain was 44%. Imagine if you could cut both fuel usage and environmental emissions by ~40% simply by changing a prop. The competitive advantage of changing props could drive a close to 1% reduction in overall CO2 emissions, given that the shipping industry accounts for about 2% of global emissions. The constant smog around ports could also be partially reduced, reaping health gains. Potentially you may not need as strong a sonar emitter either, since the signal to noise ratio should be improved if you isolate out prop noise (I know, thats a long bow to draw, and they may not overlap, but still important to consider in overall oceanic health)