BBC says that a new robot shark is giving the National Marine Aquarium in Plymouth a bit of excitement. Roboshark2 is about 6' (2 meters) long and moves (swims?) via sensors and thrusters at about 3 mph. Roboshark2 is directed by its electronic brain and can also be operated by remote control. The Roboshark and will be in the tank with four other real sharks for a period of three years to see how the other sharks react to it. The roboshark's batteries only last about 4 hours so it has to be removed and recharged periodically. The first Roboshark known as Roboshark1 was a hastily built robotic shark shell built for a BBC TV series that filmed sharks up close and personal via a hidden camera. This new Roboshark2 is high tech and puts the previous roboshark to shame and is much better at fooling sharks into thinking it's just another friend to swim with. However, this article seems to suggest that not all sharks are dumb enough to fall for this robotic imposter.