A theory is presented for wave-driven propulsion of floating bodies driven
into oscillation at the fluid interface. By coupling the equations of motion of
the body to a quasi-potential flow model of the fluid, we derive expressions
for the drift speed and propulsive thrust of the body which in turn are shown
to be consistent with global momentum conservation. We explore the efficacy of
our model in describing the motion of SurferBot [Rhee et al., Bioinspir.
Biomim. 17 (5), 2022], demonstrating close agreement with the experimentally
determined drift speed and oscillatory dynamics. The efficiency of wave-driven
propulsion is then computed as a function of driving oscillation frequency and
the forcing location, revealing optimal values for both of these parameters
which await confirmation in experiments. A comparison to other modes of
locomotion and applications of our model to competitive water-sports are
discussed in conclusion