A naval mine is an explosive device designed to be placed in water to damage or destroy ships and submarines. These mines can be anchored to the seabed or float freely and are triggered by contact, pressure, or proximity to a vessel. They are used in naval warfare to control sea routes and protect coastlines. Naval mines come in various types, including contact mines, which detonate upon physical contact, and influence mines, which activate based on changes in water pressure or magnetic fields. They have been used in conflicts since the 19th century and remain a significant threat in maritime security today.