A large number of robots have been designed to operate in or near water, whether fresh water or the salty seas. Military, homeland security, and naval operations are some of the more obvious application areas. For example, Bluefin Robotics' autonomous underwater vehicles and the Hawkes Remotes remotely-operated vehicles are designed for reconnaissance, surveillance, and detecting unexploded ordnance. Like many of their unmanned ground vehicle counterparts, they can go where humans can't.
These, and other mostly autonomous robots are also aimed at scientific exploration and data gathering, as well as maintenance of ships, oil and gas pipelines, telecommunications cables, or alternative offshore energy installations. Some target water or environmental health monitoring.
Click the image below to see 13 examples of these sea-worthy automatons.
Festo's AquaPenguin is one of many projects the company has pursued under its Bionic Learning Network. The network's purpose is to use the energy-efficient principles already found in nature and adapt them to automation technology. The AquaPenguin is an autonomous underwater vehicle with penguin-inspired hydrodynamic body contours. Equipped with a 3D sonar system, like that of dolphins, it can communicate with its surroundings and other AquaPenguins, independently orient itself, and navigate. Its torso, head, and tail sections can move in all directions for maneuvering in cramped areas, letting it turn on a dime and swim backwards. (Source: Festo)
Beth. when I looked at the details--as much as Festo will give--of their jellyfish and penguin robots I was stunned at the quality of the design. Perhaps I shouldn't have been: Festo is known for quality and clearly good design is required for underwater robots, especially autonomous ones. Their utility, at least for surveillance-type apps, seems pretty clear.
Chuck, I agree--they look so vulnerable, yet are surprisingly rugged. In fact, Liquid Robotics has just formed a separate joint venture company with Schlumberger for oil & gas exploration and production services: http://liquidr.com/files/2012/06/Schlumberger_LiquidRobotics_Joint_Venture.pdf
Ann, it would be wonderful to see the military engage in formal tech transfer programs like the national labs do. The labs have programs to send their R&D out to start-ups -- usually start-ups runs by former lab researchers. It's a great idea to make the taxpayer-financed research available to entrepreneurs. Robotics looks like a perfect candidate for tech transfer.