  A small drop of a heavier fluid may float on the surface of a lighter fluid
supported by surface tension forces. In equilibrium, the drop assumes a
radially symmetric shape with a circular triple-phase contact line. We show
theoretically and experimentally that such a floating liquid drop with a
sufficiently small volume has two distinct stable equilibrium shapes: one with
a larger and one with a smaller radius of the triple-phase contact line. Next,
we experimentally study the floatability of a less viscous water drop on the
surface of a more viscous and less dense oil, subjected to a low frequency
(Hz-order) vertical vibration. We find that in a certain range of amplitudes,
vibration helps heavy liquid drops to stay afloat. The physical mechanism of
the increased floatability is explained by the horizontal elongation of the
drop driven by subharmonic Faraday waves. The average length of the
triple-phase contact line increases as the drop elongates that leads to a
larger average lifting force produced by the surface tension.
