I'm not sure how fast I sink, but if I exhale I appear to still be accelerating when I hit the bottom of the deep part of a pool. If my lungs are full and I'm thrashing around I stay alive in the water. Exhaling, in order to inhale again, makes that staying alive process much more doubtful. That's part of the reason I'm leery. The other is giant squids and whatever else is down there.

So the car hits me, on my bike, and knocks me off the roadway into the water, where I land on a boat, overturning it...