  A body immersed in a supersaturated fluid like carbonated water can
accumulate a dynamic field of bubbles upon its surface. If the body is mobile,
the attached bubbles can lift it upward against gravity, but a fluid-air
interface can clean the surface of these lifting agents and the body may
plummet. The process then begins anew, and continues for as long as the
concentration of gas in the fluid supports it. In this work, experiments using
fixed and free immersed bodies reveal fundamental features of force development
and gas escape. A continuum model which incorporates the dynamics of a surface
buoyancy field is used to predict the ranges of body mass and size, and fluid
properties, for which the system is most dynamic, and those for which body
excursions are suppressed. Simulations are then used to probe systems which are
dominated by a small number of large bubbles. Body rotations at the surface are
critical for driving periodic vertical motions of large bodies, which in turn
can produce body wobbling, rolling, and damped surface 'bouncing' dynamics.
