I would add that I've worked with autonomous underwater vehicles. UVic has a great system from an American friend of mine. It's about the convergence.
What the flying piece does is give you a great view of the ground. The ground robot is good. Underwater is also good, but with limited communications. If you give the underwater the ability to carry a little antenna, and you have the airborne piece, you can go back and forth so you can get the data back.
Using your imagination when you think about the problem you're trying to solve, and with the flexibility to use robots, you can do amazing things.