Well, of course nobody is able to predict inventions of the future. However, the entire science of imaging, be it sub-surface or medical, be it with seismic waves or EM waves like radar or X-rays, has made a continuous development. The reason why medical imaging produces high-resolution 3D images has two reasons: the energy source is very close to the target, and more importantly, the target can be illuminated by the source from all sides. This is mostly not possible with sub-surface targets or with objects inside a sunk ship - the source mostly is only able to illuminate the target from above. It are simple physical reasons like this (and there are many others) why I don't believe that there will be dramatic changes in subsurface-imaging in the near future - but of course, one never knows what is going to happen.