Given the positioning of the data recorder, the NTSB says crews can't get to it with the current team's equipment, and that they will have to launch another mission.
"Extracting a recorder capsule attached to a four-ton mast under 15,000 feet of water presents formidable challenges, but we're going to do everything that is technically feasible to get that recorder into our lab," Acting Director of the NTSB Office of Marine Safety Brian Curtis said.
On Tuesday, NTSB crews located the recorder 15,000 feet beneath the surface.
Officials resumed the search last week with advanced sonar and imaging systems.
"Finding an object about the size of a basketball almost 3 miles under the surface of the sea is a remarkable achievement," NTSB Chairman Christopher A. Hart said.
Given that the data recorder has been submerged for seven months, the value of the data is in question. But the so-called "black box" may help answer many lingering questions about what happened to the ship during the final hours before it sank, as it records conversations on the ship's bridge.
The 40-year-old U.S.-flagged El Faro
was headed to Puerto Rico from Jacksonville, Florida, and went missing near the Bahamas on October 1 with 33 people on board. The ship's 28 American crew members and five Polish nationals are presumed dead.
The owners of El Faro said the captain had a "sound plan" to avoid Hurricane Joaquin
, but the ship's main propulsion failed, stranding the crew in the path of the Category 4 storm.
The wreckage of the nearly 800-foot container ship was located in late October. It was in 15,000 feet of water near its last known position near Crooked Island.
According to the NTSB, it was found in an upright position with the stern buried in about 30 feet of sediment. The bridge and the deck below, however, had separated and were not with the rest of the vessel.
The fact that the bridge separated presented a chilling scenario to those in the industry.
"I'm pretty sure it happened very quickly and very violently," Larry Legere, a ship captain based in Portland, Maine, said of the El Faro's sinking. "If it was enough to rip the bridge right off that ship, it was a very violent end, and probably why they didn't recover any survivors."
The U.S. Coast Guard in February opened public hearings into the disaster.