When Elisha Bennet applied for his pension (in 1818) for service during the Revolutionary War, he stated that he was "upwards of" 85 years old. His death date, 23 Nov 1821, is given on the first page of his file. Since he claims he served in the navy from January 1777 to February 1778, he was about 44 years old when he enlisted - surely one of the older men to enlist! You can see part of his application by clicking on the images to the right.
Revolutionary War Pensions: Age at time of Enlistment