Navy divers are confident that they will be able retrieve the two flight recorders when the search operation resumes on Monday.
Aircraft parts and human remains have been found.
The Sriwijaya Air Boeing 737 was carrying 62 people when it vanished from radar on its journey to Borneo.
"We have located the position of the black boxes, both of them," said Soerjanto Tjahjono, head of Indonesia's transport safety committee, quoted by AFP earlier on Sunday.
"Divers will start looking for them now and hopefully it won't be long before we get them."
