You know, once you challenged me on this I thought about a bit more and it seems its actually probably pretty hard short of using sonar off the sea floor. If y

You know, once you challenged me on this I thought about a bit more and it seems its actually probably pretty hard short of using sonar off the sea floor. If you use inertial sensors, you're in a moving fluid which really messes up your ability to dead set navigate. That said, it seems like it would be much easier for a computer to handle this than a person, especially if it had already mapped the area.