Why is a layered undergarment system recommended for cold conditions?

A layered undergarment system is recommended for cold conditions because it provides better insulation compared to a single thick suit. Layering works on the principle of trapping air in the spaces between layers, which enhances thermal insulation. Each layer serves a specific purpose: the base layer wicks moisture away from the skin, the mid-layer provides insulation, and an outer layer can add additional warmth or serve as a protective shell. This system allows divers to adjust their insulation according to changing conditions, making it more versatile and effective in various cold environments.

In contrast, while fashion might play a role in design choices, it does not contribute to warmth or functionality under water. The ease of removing a suit in water is not a significant factor for thermal protection, as the priority is maintaining heat while diving. Lastly, while a layered system might indeed be lighter and less bulky, the primary reason for its recommendation is the effective insulation that it provides, making divers more comfortable and safer in colder temperatures.