They will get it at some point though - not only are there a lot of programmers who would love to write something as complex as that, but they can afford to pay very, very well.
They basically need a GAVIA[1] system with an extra couple of battery modules and one of the dvl/ins modules to allow for long travel distances with less accumulated error. Build a payload module and screw them all together and you're there. [1]http://www.gavia.is/Products/Gavia-Technology/Payloads/