Dulany Forrest (often rendered as Dulaney) was born in either Washington or Baltimore, Maryland about 1790-95, the son of Major Joseph Forrest and Elizabeth French Dulany. He was appointed a Midshipman 23 May 1809 and ordered to report to Captain William Brainbridge aboard frigate President, where he served until that November. After a furlough, Forrest served aboard frigate Essex from March 1810 to August 1811. After undergoing tution in Washington, he was ordered to Constitution at Boston, though his name does not appear on that frigate's muster roll.

On 29 June 1813, as the conflict with England continued, Midshipman Forrest was sent to Sacket's Harbor, New York, with orders to stop at New York City and take any available recruits there to accompany him. On his arrival on Lake Erie, Forrest was assigned to Captain Oliver Hazard Perry's flagship, the brig Lawrence. On 29 July, Perry appointed him an Acting Lieutenant. During the Battle of Lake Erie on 10 September 1814, he was stunned by gapeshot and fell at Perry's feet. Perry raised him to his feet, and once recovering his senses, asked if he he was seriously hurt. Forrest replied "I am not hurt, sir, but this is my shot," extracting the grapeshot and cooly placing it in his pocket. After the American victory, he had the honor of carrying the captured British flags to Washington.

On 02 February 1814, he was ordered to report to sloop-of-war Argus at Washington to serve as one of her lieutenants. In April, he was detached and sent to the Erie Station, where he served until July. fter another furlough, Forrest was ordered in October to join the frigate Epervier at Savannah. Serving in her at New York in April 1815, he wrote he was not well and wished a transfer to the frigate Java under Captain Perry. He served aboard this vessel until at least 1817, both in home waters and the Mediterranean. While serving on Java, Forrest was promted to Lieutenant 30 November 1815, to date from December 1814. In May 1818, he wrote from aboard frigate John Adams requesting command of Gunboat No. 168, which vessel he commanded into late 1819. During 1820-1822, Forrest served as Washington Navy Yard, commanding the yard's tender, Gunboat No. 67. After briefly being assigned to sloop Peacock, Forrest apparently was waiting orders until being ordered to command of Beagle in the West Indies Squadron during March 1825. He commanded both Beagle and Propise while fighting Carribbean pirates. On 01 October 1825, he died of yellow fever aboard store ship Decoy while on passage to Havana.