They're still anecdotes ... you have no scientifically objective data with which to argue against basic physics.
And yes, I do agree that technique is a contributing variable through elements such as kick efficiency - - but the scientific process examines only one variable at a time. The only variable under discussion here is the BC.
Yes, there's variation based on fitness. For example, a Tour de France elite athlete can sustain ~300 watts for an hour, but a power lifters can output up to 1800 watts ...but only for a few seconds. An average person will typically only be able to output ~125W over an hour ... which means the elite athlete is roughly only ~2x better.
Incorrect: I'm recognizing that elite athletes aren't representative of the 50th percentile human. They represent the 1% extreme.
Besides, haven't you noticed the obesity epidemic in the USA, Dan? If fitness were such a huge contributor, then shouldn't PADI be flunking more students?
What's easier still is to drag each diver behind a boat ... it eliminates the variable of diver fitness and does a better job of testing just the dive gear. Of course, Lee Bell offered to do this ... ten years ago ... and the salesmen making the "Our Gear is Best" claims ran away.
Hint: PAID OW, AOW, Rescue, DM, AI & Instructor standards don't require elite athlete performance minimums.
For mere seconds, such as a Power lifter.
Unfortunately, scientific papers that have measured the performance elite cyclist athletes have hard data that says otherwise.
Here's but one example. And
here's another. The measured science says that the difference is nominally only 2:1.
Now if we apply that 2:1 ratio to diver swimming velocities, for the same technique, fin, BC, etc, etc, etc ... the elite with 2x the available power is only going to be able to be SQRT(2) faster: +41%. That means 1.41 knots if the average diver is only able to do 1 knot max.
Immutable Physics. That's what you're trying to argue against Dan, not me.
-hh
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The smoke screen exists because from a marketing standpoint, divers - - especially new ones - - believe the hype.
That's how we've had fads before for many other dive widgets before this: brightly colored wetsuits, changes in training course names, fins with special vents, wetsuits with special linings, Force Fins, Split Fins, plastic balls that you release into the water that ascend at exactly 60ft/min, BCs that have depth-sensitive auto-inflation devices on them, self-deploying SMBs, Spare Air, ... the list of new, supposedly "better" equipment for divers to buy goes on and on and on.
-hh