Marine Toilet
A marine toilet, also called a vacuum toilet or ship toilet, is used on boats and ships of all types and sizes. Marine toilets work by removing the waste from the bowl by suction and then depositing it in a holding tank when the toilet is flushed. Traditional toilets, such as those found in the home, use a combination of water and gravity to transport the waste from the bowl to a collection or treatment tank.
Like regular toilets, marine toilets use water to flush although in far smaller quantities - typically around 1.5 liters of water per flush as opposed to the 10 liters used by a non-vacuum toilet.