Thermal differences in the sea and their effect on diving

Water is not the same temperature from the surface to the bottom. Thermal differences affect both diving and the environment.

Thermocline

The thermocline is the boundary between a warm layer of water above and a colder layer below. You feel it as a sudden shift in temperature during descent.

Effect on vision

At thermocline, the dividing line appears as a wavy glass or hazy layer. Vision is sometimes noticeably affected.

Effect on balance

The density changes with the thermocline, and this means that lead settings that work well above the thermocline may not work as efficiently below it.

The effect of thermocline on marine life

Many fish concentrate at the thermocline because marine plankton accumulate at this point. A diver who knows thermocline knows where life is.

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Knowing the sea layer by layer gives you a deeper understanding of what you see and where to find on every dive.