well ive personally witnessed a reading of 8% bf done professionaly, and the guy looked basically the same as Pitt in terms of definition.
in my practice I use three methods to measure bf:
infrared spectrophtometry
Skindex
Fatometer caliper
The Infrared device cost $12,000
The Skyndex $700
The Fatometer plastic caliper, about 10 bucks
And, would you believe the 10 dollar device is most accurate, as far as reproduceable results go...
I used to occasionally engage hydrostatics in studies at our University, but not feasable dt the fact that some subjects were averse to being submerged...