Interesting methodology. I start out with no air in my bc and end with no air in the bc. I rarely add air to my bc during the dive. Proper weighting and breathing control minor ups and downs (yes, I do take a big breath and hold it to go over a coral head then release it and drop back down, eek holding breath eek). Clear blue water decent and acent have at least one eye pretty much pegged on my computer. If I'm in a hurry to get down (ie in strong current conditions a slow decent may put you somewhere Waaaay away from the dive site) I , and my buddy point head down and swim straight down, clearing ears as we go.