  We consider two- and three-dimensional gravity and gravity-capillary solitary
water waves in infinite depth. Assuming algebraic decay rates for the free
surface and velocity potential, we show that the velocity potential necessarily
behaves like a dipole at infinity and obtain a related asymptotic formula for
the free surface. We then prove an identity relating the "dipole moment" to the
kinetic energy. This implies that the leading-order terms in the asymptotics
are nonvanishing and in particular that the angular momentum is infinite.
Lastly we prove a related integral identity which rules out waves of pure
elevation or pure depression.
