A Norwegian munitions company claim to have created a "new breed of ammunition" that is capable of "swimming" underwater to obliterate targets.
DSG Technology say they have developed and sold 'supercavitating' ammunition that can be used from air to water, water to water and water to air, including partially-wet weapons.
Supercavitation is described as an effect that creates a bubble of gas around an object submerged in a liquid to allow it to travel through liquid at a greater velocity and travelling further distances.
The company, based in the nation's capital, Oslo, say the ammunition gives unique capabilities for Special Operations, diver support, harbour protection, anti-piracy and submerged shooting positions.
The CAV-X bullets were sold to several unnamed countries and international militaries earlier this year, with the United States Navy reportedly interested in the product.
The company, which is also based in Cyprus, has also offered the bullets to NATO.
"You can fire from a helicopter and take out a sub if you have a big enough caliber," DSG director of Special Operations Forces Kristian Asknes told Military.com.
"Many countries are trying it out," he continued. "And hopefully they'll come back and buy more."
Asknes did not confirm which countries had purchased the bullets, but said the DSG "fielded interest" from the US military.
The bullets come in 12.7mm, 7.62mm and 5.56mm rounds, as well as for smaller weapons.
Made from tungsten with a brass shell, the bullets work by creating an air pocket thanks to a turned tip and precisely calibrated mass and balance, a company spokesman revealed.
They can also be used with conventional weapons, with Aksnes adding that the technology is completely scaleable.
The company's official website says that the 12.7mm bullet, designed to be fired from a machine gun, has an effective range of 2,200 meters through the air and 60 meters underwater.
While the 7.62 and 5.56 rifle rounds are effective underwater at 22 and 14 meters, respectively.
The company also have a patent-pending underwater gun mount (UGM), designed to be fixed on unmanned underwater vehicles and ships.