Transverse wave. Animation shows the propagation of elastic wave in a grid which consists of the balls connected each other by springs. The oscillation in transverse wave occurs in the direction perpendicular to the direction of the wave propagation.

Longitudinal wave. Every ball oscillates harmonically in longitudinal direction, which coincides with the direction of the wave propagation. All the balls in a longitudinal wave oscillate with equal amplitudes, while the phase of oscillation increases linearly from ball to ball.

Superposition of transverse and longitudinal waves of equal amplitudes shifted by phase at 90 degrees. As a result every ball moves in a circle path.

The molecules on the water surface move under the action of surface tension and gravity. If the amplitude of the wave propagating on the water surface is small, then every ball, which simulate a molecule, will move in a circle path. The radii of these circles are diminishing with the depth, so the balls in bottom part of animation are still.

The waves on the surface of the water are neither longitudinal nor transverse. We can see in animation that red ball, which simulates the molecule of the water surface, moves in a circle path. So, the wave on the water surface is the superposition of transverse and longitudinal motions of the molecules.