The infant female, who was naked, was discovered by an off-duty Boynton Beach firefighter who had been boating at the time.
The sheriff's office released an artist's rendering of how the baby likely appeared at birth.
The newborn was recovered around 1 p.m. Friday but the sheriff's office does not know how long the baby was in the water.
"It's gut-wrenching and we hate seeing it and we really, desperately want to get to the bottom of what happened," said PBSO Special Victims Unit Capt. Steven Strivelli.
The Palm Beach County Medical Examiner's Office still has not determined the cause of death.
Investigators ask anyone with information to call Call Detective C. Hamilton 561.688.4155 or email Hamiltonc@pbso.org.
We are seeking the community's assistance to identify this baby found Friday, June 1st on the ocean side of the Boynton Beach Inlet. The female infant was no more than 14 days old. Anyone with information please call Det. Hamilton at (561)688-4155 or email firstname.lastname@example.org pic.twitter.com/RxcSAJznBp