After proposing aerial fulfillment centers,, Inc. (AMZN) has now trained its sights underwater. The Seattle-based company was recently granted a patent to develop "Aquatic Storage Facilities" for its packages. (See also: Amazon Wants to Build Warehouses in the Sky.)

The facilities would consist of a storage pool with a conveyor belt, a sonar transducer (to emit sounds) and a computer device that would be in communication with the sonar transducer to regulate the flow of packages within the pool. In its patent, the company has outlined a number of problems with land warehouses, such as inefficient use of space as well as the distances that staff members or robots have to walk within the warehouse itself to fulfill customer requests. The aquatic storage facility proposed by Amazon could be a potential solution for those problems because it can be used in natural bodies of water, such as Lake Union in Seattle, and uses a combination of automation and natural flows to store and move objects. (See also: The Dreamers of Silicon Valley: Amazon, Facebook and Google.)

Here's how the system would work. Packages are dropped from the air or placed into a liquid container facility or natural body of water. They float to a desired storage depth, based on manipulations by the computer device. For example, the device may charge a package with additional water or air volume to make it sink to the prescribed depth. In certain cases, the package will use the natural flow of water as transport to its storage spot.

When the package is ready to be shipped, the sonar transducer will emit a sound that will trigger a parachute kept in a cartridge attached to the package. The parachute will propel the package upwards until it reaches the surface, where it may be picked up by an Amazon employee, aircraft or drone. Amazon's design for a warehouse underwater seems complementary to its plans for one in the air. For example, both designs make extensive use of cartridges attached to packages to ensure safe and accurate transport. This means that the company may, in the future, redesign its packaging at scale to suit these methods. (See also: Unwrapping Amazon's Logistics Moves.)

While the system's design may sound futuristic, Amazon's intentions, as far as logistics and warehousing are concerned, are not. The Seattle-based company has made aggressive moves in recent times to speed up its delivery times and ensure greater efficiency at its warehouses. For example, it recently inked a partnership with fuel cell maker Plug Power Inc. (PLUG) that will make it a prominent player in the fuel cell-operated forklift industry. Amazon was also a pioneer in using robots in its warehouses to automate tasks. (See also: Why Is Amazon Interested in Plug Power?)

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