"Neutral buoyancy is like the flat spot on a hilltop where a ball will not roll. Once it's pushed from that spot in either direction, however, it gains speed. Too much lead on your weight belt, and therefore too much air in your BC, makes the flat spot smaller and the slope on each side steeper."
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.