The similarities between ROVs and UAVs are striking. In particular, the fact that OROV uses Arduino as part of its control system. Both UAVs that I have built/owned use an Arduino-based autipilot called APM. The software that we use to control it from an Android phone or tablet can be found here:
This basically leverages GPS and telemetry uplinks to tell the "drone" to follow the tablet PC or phone. Pretty cool, huh? I have an idea. Tell me if you think this might be a workable solution for OROV.
Would it be possible to write a portion of code that would allow the OROV to communicate with a UAV and follow that UAV? If you kept the OROV to a depth less than about 2 feet, you could conceivably obtain GPS lock or even affix a combination GPS/telemetry "periscope" of sorts to allow GPS/telemetry comms. Program your desired NAV WPTs into the UAV and tell the OROV to follow it. Once OROV arrives at a WPT, it dives to a specific depth, does its thing, then ascends back to the surface for the next WPT. If you were using OROV for aquatic sampling or undesea archaeology, the OROV would be able to log GPS position with each dive and each ascent. It isn't the most accurate way of doing this, but it might work. I am not much of a programmer, but I do dabble in Python a bit.