cool_hardware52
Contributor
Where's your tank position in relation to the cam bands/wing. If the tank is sitting too high that'll throw you forward. Quite a few people who go to a BP/W without someone experienced helping them set it up end up with the tank too high and pitch forward.
Yup, or too low.
Me? The tank belongs where I have the best chance of reaching the valve, and adjust trim around that.
It's also pretty common for divers to be butt heavy and over compensate with body position and end up falling forward, particularly with singles. The reverse is often true in doubles.
What I recommend is:
1) Determine your idea total ballast
2) Find a dive site with a horizontal bottom that is ok to lie on, institutional pools are great.
3) Dump your BC and lie face down, get into the "skydiver" position
4) Add puffs of gas to your BC until a big deep breath just lifts you off the bottom.
5) If your knees are on the bottom and your chest is rising you need to move ballast north, for example from a belt to the plate, or raise the tank position. (This is the most common condition for single tank divers) If your chest is on the bottom and your knees are floating away move ballast south.(This is more common in doubles)
Repeat with a near empty tank to see if you need to compromise ballast location.
Done.
Tobin