Revan has an agenda... to sell gear, it seems. His research is going to support his agenda, regardless of the realities. He thinks he's significantly faster with his fins (and other "efficiency improvements") and can sustain such speeds to the betterment of his diving experiences. He also seems to think that everyone wants to dive faster. His world view doesn't seem to match everyone else's but some of the things he's doing are at least interesting. And he's decided (or at least stated) that he's not going to answer any more questions in this thread. I'd say let it go, folks.