WASHINGTON — The National Transportation Safety Board said Tuesday that its investigators had found the missing data recorder belonging to El Faro, the hulking cargo ship that sank last fall with 33 crew members on board.

Investigators had already found the sunken ship and debris on the ocean floor, but had not found the recorder, which they believe holds clues to the the final hours of the El Faro.

“Finding an object about the size of a basketball almost three miles under the surface of the sea is a remarkable achievement,” Christopher Hart, chairman of the NTSB, said in a statement Tuesday.

The NTSB had said earlier this month that it would resume the search for the missing data recorder, which the agency says could hold “critical information” for investigators. While the device has been found, authorities now say the next step is to figure out how they can actually retrieve it.

This device could contain navigational data as well as voice recordings from the navigation bridge of the ship in the hours before it went down during Hurricane Joaquin. El Faro was heading from Jacksonville, Florida, to Puerto Rico in October when the ship sent out electronic distress alerts.

A research vessel owned by the U.S. Navy will remain in the area to document the sunken ship through Saturday before returning to Massachusetts, the NTSB said.