What is the primary purpose of a dry suit?

The primary purpose of a dry suit is to provide thermal insulation and keep the diver dry in cold water environments. This is essential for divers who are operating in colder conditions, as maintaining body temperature is critical for safety and comfort during dives. Dry suits are designed to create a seal that prevents water from entering, allowing the diver to wear insulating layers underneath.

The insulation provided by the suit helps retain body heat, reducing the risk of hypothermia. In contrast, the other options focus on functions that dry suits do not primarily serve, such as buoyancy or mobility. While some dry suits may offer buoyancy characteristics, their main function is not to enhance buoyancy or increase weight, but rather to maintain warmth and dryness. This makes option B the correct choice, as it accurately captures the essential role of a dry suit in diving scenarios.