The bottom wave has a greater ____

amplitude

surfboard collection!

To determine which wave has a greater value, more information is needed. The term "bottom wave" is ambiguous and can refer to different wave properties, such as amplitude, frequency, wavelength, or phase difference. Please provide more specific context or information so that I can answer your question accurately.

In order to provide a complete answer, I need to know the options you are referring to. Could you please specify what the two options are for comparison?