Strong currents and blinding silt thwarted an attempt by divers to find AirAsia Flight 8501’s black boxes Thursday, which they hope are still located in the recently discovered tail of the plane.

The flight data and cockpit voice recorders, which are crucial to helping determine what caused the jet to go down with 162 people aboard on Dec. 28, are located in the rear of the aircraft.

AirAsia black boxes

A day after an unmanned underwater vehicle spotted the plane’s tail, lying upside down and partially buried in the sea floor, divers were unable to make it past choppy seas and 1-meter (3-foot) visibility, said National Search and Rescue chief Henry Bambang Soelistyo.

He said expert teams from Indonesia and France were looking at other options, including a crane to lift the tail.

Ping-emitting beacons in the black boxes still have about 20 days before their batteries go dead, but high waves had prevented the deployment of ping locators, which are dragged by ships.

A total of six ships with ping locators were in the search area in the Java Sea, said Nurcahyo Utomo, an investigator of the National Commission for Transportation Safety.

He said that based on pictures taken by the divers, he believed that the black boxes were still attached to their original location.

“Once detected, we will try to find and lift up the black boxes as soon as possible,” he said.

The tail wreckage, identified by the plane’s registration number and part of the AirAsia logo, was located Wednesday about 9 kilometres (6 miles) from where the Airbus A320 carrying 162 passengers and crew lost contact with the control tower on Dec. 28. The plane was nearly halfway between the Indonesian city of Surabaya and Singapore.