As they clung to the hope that the five-person crew of the Titanic was still alive and could be saved in the few remaining hours of air, search teams looking for a submersible near the ship’s wreck called in specialized deep-sea recovery equipment.

Since the ship went missing on Sunday while doing a dive to survey the Titanic, a fleet of search ships have gathered in the North Atlantic about 1,450 kilometers east of Cape Cod, Massachusetts.

The US Coast Guard said on Wednesday that the Navy is sending a lifting system to the area that can retrieve aircraft or small boats from deep water that are large and heavy and have gone down.