One person has died following a water-related incident near Big Manly Beach, Manly.

Emergency services responded but the person was located deceased.

In a separate incident, about 4.30 p.m., emergency services received a report that a person had "encountered trouble" in the water near Narrow Neck Beach in Devonport.

They were carried to shore but were unable to be revived and died, according to a police spokesperson.

Both deaths will be referred to the Coroner.