USS Coral (PY-15), previously USS Sialia (SP-543), was a yacht in commission in the United States Navy as a Patrol Yacht from 1940 to 1943.

Coral (PY-15) was built in 1913 by Pusey and Jones, Wilmington, Delaware.

Coral made two Naval Reserve cruises from Philadelphia during June 1941, then sailed 30 August for Newport and inshore patrol duty until 8 October.

After training at Guantanamo Bay, she served at Key West, Florida with Service Squadron 9 until decommissioned 12 August 1943.

This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.