What you would have to know to classify a wave as either a deep- or shallow-water wave

The two physical parameters which are very essential in order to distinguish between deep- or shallow-water waves are –  

a)Water depth at which waves are produces

b)Length of the waves

A shallow water wave has low water depths and long wavelength while vice versa is the case of long water waves. For example - Tsunami is considered as a shallow water waves as it has length of waves more than 100 kilometer which reached the maximum height in a period of 10 seconds.  

depth

Explanation:

depth is the Greatest way due to what it is, depth is the measurements of the how deep something is from surface to sea floor, such as

"this hole is 115ft deep" if it's starting top to bottom the hole's depth would be 115ft

that will show depth

So depth would be the best option