A method used In offshore operations, particularly in deep water for repositioning a drillship or semisubmersible drilling platform over a hole previously drilled and cased. The technique employs acoustic signals emitted by equipment onboard the ship which are "bounced off " the submerged wellhead indicating to receivers the location of the hole. In hostile environments such as a severe storm or encroaching ice, a drillship may be forced to move off location before the well is completed. And although the operators of the drilling vessel know the approximate location of the temporarily abandoned well, to be able to reenter the hole without diver assistance, which often is not possible, requires the pinpointing of the location by electronic means.
