The ocean has a mysterious quality about it, doesn't it? Its depth and darkness make it difficult to see what lies beneath.

Modern technology has made it a bit easier to navigate the sea, but you can imagine that port security is still a major concern since illegal items are often smuggled through international waters due to the size of vessels and the difficulty of accessing them.

However, researchers at MIT may have come up with a solution. At the recent International Conference on Intelligent Robots and Systems, researchers revealed their creation: an oval-shaped, underwater robot that can slide along beneath the sea to perform ultrasound scans. The robot can be used to inspect ships for the false hulls and propeller ships that people use to smuggle in contraband.

The robot was originally designed to search for cracks in the water tanks of nuclear reactors. However, at only about the size of a football with a unique way of propelling itself and leaving no visible trace, the robot has the potential to be hidden in algae or other types of camouflage. Then, it could covertly swim up to ships at port to see if they are smuggling in contraband without the ships getting rid of their cargo first.

The robot was designed by Sampriti Bhattacharyya, a graduate student in mechanical engineering, and her engineering professor Harry Asada. They built much of the robot using a 3-D printer. Half of the robot is waterproof and contains the electronics, and the other half has a six-pump propulsion system that releases water through rubber tubes.

The prototype of the robot hasn't had its ultrasound sensor yet because the researchers just wanted to see if the robot was able to navigate underwater and stay in contact with the researchers while moving in a straight line. The next prototype will be equipped with wirelessly rechargable batteries that will increase the robot's running time from 40 minutes to 100 minutes. It will also feature modifications to its propulsion system.

The robot's ultrasound sensor may be a challenge for Bhattacharyya and Asada going forward. Ultrasound only works when the emitter is in direct contact with the object it wants to scan or when its distance is a certain multiple of a wavelength of the sound. The hard outer coatings of many hulls may make continuous contact difficult. Bhattacharyya and Asada are trying to develop a way for the robot to use ultrasound without being in direct contact with the ship.

Bhattacharyya said in a statement that using these robots could potentially be less expensive than using "traditional robots" for port security. If Bhattacharyya and Asada do find a more cost-effective way of keeping tabs on what ships are bringing into ports, this could mean greater port security, which in turn could mean greater security overall.