Depth Sounding

I checked the floating watermelon seed inside the glass tumbler. Still steady in the center. I needed an accurate depth measure of the liquid floor. I drew the notched toothpick pike from my vest straps, gripped the blunt end, and lowered the tapered tip straight down over the rim. The birch wood broke the surface with a faint ripple. I touched the bottom glass pane and counted four grip notches submerged below the waterline. Exactly eight millimeters of clearance. I pulled the pike back up, wiping the wet wood dry against the blue painter's tape on the tumbler wall before stowing it.