What term describes the valley between waves?

The term that describes the valley between waves is "trough." In oceanography and wave dynamics, a trough is identified as the lowest point in a wave cycle; it is where the wave's energy is at its minimum and is located between two successive crests, which are the highest points of the waves. Understanding this concept is essential for Coxswains as it aids in interpreting wave patterns and behavior, crucial for safe navigation and operation of vessels in marine environments.

The other terms do not accurately describe this specific area between the waves. "Trench," for example, typically refers to a deep, narrow depression in the ocean floor, often associated with tectonic plate boundaries rather than surface wave dynamics. "Hollow" tends to imply a larger void or empty space, which does not correspond to the defined low point of a wave. "Depression" can denote a low-lying area in a broader context, but it doesn’t specifically pertain to the technical aspect of wave formation and structure. Thus, "trough" is the precise terminology used in marine science for the valley between waves.