Ridley Township police said the divers, who are volunteers with Adventures With Purpose, had been contacted by Amabile's family, who hoped to help provide closure as to what happened to their loved one.
"When the man went missing on December 4, 2003, he went to pick up two children from the babysitter and never showed up at the babysitter's house," said Captain James Dougherty of the Ridley Township Police Department during an interview earlier this month.
The divers called police after making the grisly discovery on March 19.
SEE ALSO: Missing man's remains found inside submerged vehicle in Ridley Township, officials say
On Tuesday, officials with the medical examiner's office said they were able to identify Amabile through dental records.
Adventures With Purpose says it specializes in cold cases where vehicles are involved. It uses sonar technology to track them underwater.
Police say the docks have not been replaced in the nearly 20 years since Amabile went missing, and divers say one of the dock's piling punctured the hood of the vehicle.