The US Patent and Trademark Office (USPTO) has recently awarded a patent to Boeing for its new type of unmanned aerial drone that can be converted into a small submarine.

If ever built, the rapid deployment air and water vehicle would be adaptable for both flight and water travel.

Powered by a propeller, wing and stabiliser, the vehicle would be launched aboard a large carrier aircraft to reach the deployment area.

The remotely piloted aircraft would then detach from the carrier aircraft, and operate on its own, diving into water.

"The proposed drone would detach certain components using explosive bolts or a saltwater-soluble glue, in order to optimise its hydrodynamic properties."

Upon hitting water, the proposed drone would detach certain components using explosive bolts or a saltwater-soluble glue, in order to optimise its hydrodynamic properties.

A second set of components, including water-borne propellers and control surfaces, would be capable of transforming the drone into a manoeuvrable underwater vehicle.

Both air and water propulsion would be managed by a single engine, Business Insider reported citing Boeing’s patent application.

During underwater missions, the unit would have the capability to deploy its payload of weapons, and use onboard ballast tanks to control its depth.

The drone also is designed to perform undersea reconnaissance.

When the underwater mission is complete, the drone would then surface and communicate the collected data to other drones, or a command centre.

Last month, the USPTO granted a patent to a new propulsion concept by Boeing that uses laser beams to vaporise nuclear material within thrusters.