I think instead of denying that some people have issues with back inflate BCDs pushing them forward, which can definitely happen, it would be more constructive to say it should not happen with correct inflation, weighting and weight distribution.
When I was a new diver I rented a back inflate BCD to quarry dive in a 5/7 wetsuit. I'm a big guy, and with that thick of a suit I had over 20 lbs. of lead on my front and an aluminum 80cf on my back. And being new, I over inflated on the surface and absolutely could not keep from having my face thrown into the water -- even trying to lean back hard. I probably inflated even more thinking it would help, and (obviously now) it didn't.
This caused a lot of anxiety, and I had to just swim for the ladder/stairs because I could not keep my head up. I'm sure it would be quite hilarious for experienced divers to see, but I did not know any better at the time -- and I'm sure that plenty of new divers could have the same problem.
So, rather than tell people it's a myth that back-inflates or BP/W push you forward (it's not) it would be more constructive to say that it shouldn't happen if used properly, meaning that:
- People shouldn't over-inflate;
- Related to that, people shouldn't expect a back inflate to hold you as high in the water as a jacket BCD (so stop inflating);
- Lean back;
- Weight should be distributed so not all of it is in front (put some in back);
- Having too much lead in general can contribute to the problem;
- etc.
I know most people on here love BP/W, but let's not deny that new divers can have issues with back-inflates or BP/W if they don't know how to use them correctly. I'm sure the general concern of tipping forward had to come from somewhere -- and I'm guessing it probably comes from people like me who tried them when inexperienced, over-weighted, and over-inflated.
