For anyone else reading this, it's helpful to be neutrally buoyant with the lungs *fully* inflated. If you are neutral with a normal breath, then fully inhale before setting off, some of your propulsion must be directed downward (i.e., wasted) to avoid ascent. I know, it seems obvious, but in the moment easy to forget. Congrats on clearing this hurdle!To clarify, I inhaled a full breath before I began swimming.