YES ! it is possible to make a g-shock waterproof to 5000 meters : that is what I have done :
filling the watchcase with silicon fluid designed for RC models shock absorbers
here is the watch filled
and here is the 500 bars test !
the big advantage of equipressure watches is the non refletive surface under water
now the watch need to be customised to be finished : I laser engrave the back
and finishing by official pics !