What term describes the point of sudden change in water temperature while diving?

The term that describes the point of sudden change in water temperature while diving is the thermocline. This phenomenon occurs when there is a distinct layer in the water column where the temperature changes sharply with depth. In layers above and below the thermocline, temperatures are more uniform, but this transitional zone can represent a significant shift that divers may experience as they descend or ascend.

Thermoclines are important for divers to understand because they can affect buoyancy, visibility, and overall comfort during a dive. The temperature change can also have implications for marine life, as different species prefer specific temperature ranges. Recognizing thermoclines can help divers plan their dives better and be aware of the environmental changes they might encounter underwater.

The other terms mentioned do not specifically refer to temperature changes. A current refers to the flow of water, which can impact visibility and safety, but does not pertain directly to temperature. Upwelling describes a process where deep, cold water rises to the surface, often bringing nutrients with it, but it does not directly define sudden temperature changes at a specific depth. Wavelength pertains to the physics of waves, such as light or sound, and is unrelated to water temperature changes.