My ice season is underway here is Mass, and as I went about my fishing on my last trip, fishing on the bare minimum, I began to wonder: Is it the buoyancy of the ice that supports my weight, or its rigidity? I'm pretty sure I've heard stories off people drifting off on ice floes when the shelf they were standing on detached from shore, so I can assume ice floats well enough to remain on the surface even when burdened by body weight. Is that all that is keeping me topside, or is there more to it? For that matter, how did the benchmark of 4" of clear ice come about?