The team from Johns Hopkins University Applied Physics Lab has developed a drone named CRACUNS (Corrosion Resistant Aerial Covert Unmanned Nautical System) which is capable to stay underwater for months and wait until it got a command to fly.
It is designed to stay undamaged under high pressure so it is capable to stay in submerged mode at the hundreds of feet beneath the surface of the water.
The drone is corrosion-resistant – during the testing CRACUNS units were kept up to two months in corrosive saltwater and were showing no signs of any damage when they “woke up”.
The drone was built on budget and it is made from relatively inexpensive materials. Some of its components were 3D-printed. Sensitive parts are placed in the container which is fully waterproof. The motors of the CRACUNS quadcopter are still exposed to water but they are kept from damage by protective coating.