A man was hiking on Blake Island, which is east of Manchester, when he found the body near the island's southeast shoreline at roughly 3 p.m., according to Scott Wilson with the Kitsap County sheriff's office.
Deputies and a county coroner took a patrol boat to the island and retrieved the body sometime after 4 p.m.
According to the Washington State Parks Department, Blake Island State Park is a 475-acre marine camping park with five miles of saltwater beach shoreline. It is only accessible by boat.
Wilson could only say the woman was an adult. He said it's too early to know if foul play was involved or if anyone has been reported missing in the area.
The investigation is ongoing.