The continuing threat of naval mines has led the U.S. navy to plan some shock tests using five ton underwater bombs and a 25,000 ton amphibious ship. Four bombs will be used, and the ship will be equipped with sensors to register the strength of the shock wave on the ships hull, and what stress the shock wave imparts. The ship will be far enough away to prevent any damage, but close enough so that scientists can get an accurate idea of what kind of explosives, what distance away, will do what kind of damage. The purpose of the tests is to measure the impact of bottom mines.  The most dangerous, and common, naval mines are bottom mines. There are so named because they line on the ocean bottom in shallow coastal waters. Using various passive (they don't emit any signals) sensors to detect ships overhead, the mines detonate, sending a shock wave up to sink or severely damage the ship. If it's a small, or poorly constructed, ship, the shockwave will cause enough damage to open the hull and sink it. Otherwise, varying amounts of damage will be done. This will range from shaking the engine enough to shut it down, damaging electronic and other equipment, throwing crew members about and injuring them and causing minor leaks in the hull. The four bomb tests will give naval architects a better idea of how to change their construction techniques to minimize damage from bottom mines.