What type of waves move through water that is shallower than 1/20 of their wavelength?

Waves that move through water shallower than 1/20 of their wavelength are classified as shallow waves. In this context, shallow waves are significantly influenced by the bottom topography of the ocean floor. As these waves travel into shallower waters, their speed decreases and their height increases, leading to a more pronounced wave shape. The interaction with the seafloor causes changes in their motion, which is distinctly different from how deep water waves behave, where the motion is not influenced by the ocean's bottom.

Transitional waves occur in water depths between shallow and deep, while capillary waves are small ripples formed primarily by the wind on the water's surface and are generally less than one wavelength in size. Deep waves, on the other hand, exist in deeper waters where the water depth is greater than half the wavelength, allowing them to move without being affected by the seafloor. Hence, shallow waves are specifically defined by their behavior in shallow water conditions, making them the correct choice in this context.