An oscillating Cartesian diver to study pressure in fluids

We suggest a modification to the classical Cartesian diver experiment, wherein the diver operates within a fluid with density stratification rather than uniform density. Unlike the conventional setup, under a given external pressure, the diver achieves a stable equilibrium at a specific depth where its density matches that of the surrounding fluid. By adjusting the applied pressure, its density changes and it moves towards a new stable equilibrium at a different depth. When subjected to a sudden pressure pulse, the diver density changes and it starts oscillating driven by a restoring force with a frequency dependent on the density gradient.