Hardtacks are biscuits that are baked using flour, water, and sometimes salt, which are known for their high longevity and calorie density. Synonyms for hardtacks include pilot bread, ship's biscuits, sea bread, and navy bread. These hard and dense crackers have been used as a staple food item for centuries by seafarers, explorers, and military personnel due to their long shelf life and ability to survive extreme weather conditions. Besides being used as a food item, hardtacks have also been used as a sturdy building material and as emergency medical bandages. Regardless of their name, hardtacks have been a crucial food resource for countless individuals throughout history.