Scuba divers require oxygen tanks because the concentration of dissolved oxygen in water is insufficient for human respiration. The partial pressure of oxygen in water is too low under normal conditions, making it impractical for divers to extract breathable oxygen directly from the water. Unlike carbonated soda, which can release gas when opened due to oversaturation, the oxygen in water is not readily available for breathing. Submarines utilize different technology to extract oxygen from water, but this process is not applicable to scuba diving. Therefore, divers rely on tanks filled with compressed air to ensure an adequate supply of oxygen while underwater.
