Which chemical is most commonly used for water purification on ships?

Calcium hypochlorite is the most commonly used chemical for water purification on ships due to its effectiveness and stability as a disinfectant. It releases chlorine when dissolved in water, which helps eliminate bacteria, viruses, and other pathogens that may be present in the water supply. This compound is favored in the maritime environment because it has a longer shelf life compared to other chlorine compounds and is effective at various temperatures, making it suitable for the diverse range of conditions ships encounter. Its solid form allows for easier storage and handling on board ships, contributing to its popularity in ensuring safe drinking water for crew members.