( CNN ) -- The Navy detonated a large device described as being similar to a mine off the coast of Bay Head , New Jersey , Wednesday morning , sending a plume of water more than 100 feet in the air . The device , suspected to be either a moored or contact mine , was discovered Tuesday evening by a swimmer off the coast of Bay Head , about halfway between New York City and Atlantic City . The device was mostly buried in the sand , which made it hard to identify , according to Mike Brady , public affairs officer for the Naval Weapons Station Earle . An explosive ordnance disposal team was sent to detonate the device . The team determined the safest time to detonate the large device , which Brady said weighed several hundred pounds , was during the next high tide at 11 a.m. Wednesday . `` Out of an abundance of caution , we asked the local police to evacuate about 15 families from their homes in the immediate area while the detonation occurred , '' said Brady . The device was about 100 feet from the shoreline in 12 feet of water when the detonation occurred . There were no injuries . Brady said CNN it 's unclear how the device got there or how long it had been there . It 's possible the device may have moved during Superstorm Sandy , but it may never be clear where it came from . A piece of the device was secured and will be analyzed for clues about its origin . `` It 's believed this is a one-of-a-kind event , and there do not appear to be any other devices in the area , '' Brady said . Shipwreck hunters stumble across mysterious find .
The CNN 's detonation of a mine-like device shoots water several hundred pounds high . How the device weighing 100 feet got near coast is unclear . Fifteen families were evacuated as a precaution ; no one was injured . Leftover parts of the device will be analyzed for information about its origin .