Hi JMG,
Welcome to the Ask an Expert Forums. If I'm understanding you correctly (and please correct me if I'm wrong!), you want to build an underwater robot. Is your goal to build a robot so that you can answer a particular science question? Or if your goal to be build a
better underwater robot? If you are using the robot to study a scientific question, then your project will probably follow the scientific method and it would be appropriate to formulate a hypothesis. But, if your interest is in engineering an underwater robot to fill a specific need, then your project might be better suited to the engineering design process. Science Buddies has an excellent guide to the engineering design process.
https://www.sciencebuddies.org/science- ... uide.shtml
Some underwater robots can "see" in the sense that they can record video or take pictures and relay those images to a control room where people can see them. It might be interesting, however, to try to improve on current capabilities (if you are interested in an engineering focus). Or, you could think of scientific question you could investigate using an underwater robot. Perhaps it would be interesting to measure how much light it takes for an underwater camera to take a reasonably good picture. The amount of light in the ocean (or a lake, etc.) decreases as you go down the water column, so you could do an experiment investigating that, if you wanted to.
Science Buddies has some great resources on robotics. These ideas aren't as complicated as the OpenROV appears to be, but I suspect you could engineer a simpler underwater robot that would meet your design criteria. Check out the Project Ideas in the Robotics interest area to get a sense for how you might go about designing and building your own robot.
https://www.sciencebuddies.org/science- ... a=Robotics
This Project Idea shows one way of making a simple, waterproof underwater robot:
https://www.sciencebuddies.org/science- ... p002.shtml