Born on October 5, 1736, in Falmouth, Massachusetts, David Coats (also spelled Coat or Coate) was a prominent mariner and military officer in the Revolutionary era. He married Mehitable Thurston in Newburyport in 1765, and they had one daughter, Elizabeth, born in 1766.

Coats played a vital role in both civic and maritime affairs. Before the Revolutionary War, he captained vessels for merchants Nathaniel Tracy and Jonathan Jackson. A founding member of the Newburyport Marine Society in 1772, he rose to serve as its Deputy Master from 1782 until his death in 1791.

Capt. Thomas Thomas assisted in the formation of the company now known as the Newburyport Veteran Artillery Company, and was its first commander, with Capt. David Coats as captain/first lieutenant. Capt. Michael Hodge as first lieutenant, Capt. Samuel Newhall as second lieutenant, the company was formed in the winter of 1777 and its four principal officers were members of the Marine Society. In July, 1778, as volunteers they participated in the Battle of Rhode Island, the first attempt at cooperation between French and American forces, and the largest battle in New England.

During the war, Capt. Coats commanded one of four private vessels dispatched by Newburyport merchants to challenge British control in Penobscot Bay. He was captured in 1780 and later excused from Marine Society dues due to his imprisonment. His name also appears as commander of the privateer Grand Monarch, a 16-gun ship operating out of Newburyport with 45 crew members.

Coats served as a selectman and represented Newburyport in the Massachusetts legislature from 1783 to 1785.