Born at Great Egg Harbor, New Jersey, he was appointed midshipman on 25 April 1797 and served in the West Indies during the Quasi-War with France in frigate United States commanded by Captain John Barry. Promoted to lieutenant on 21 May 1799, Somers was detached from United States on 13 June 1801 and ordered to Boston on 30 July 1801. He served in the latter frigate in the Mediterranean. After Boston returned to Washington, DC, Somers was furloughed on 11 November 1802 to await orders.
On 5 May 1803, Somers was ordered to Baltimore, Maryland, to man, fit out, and command Nautilus, and when that schooner was ready for sea, to sail her to the Mediterranean. Nautilus got underway on 30 June, reached Gibraltar on 27 July, and sailed four days later to Spain. He then returned to Gibraltar to meet Commodore Edward Preble, in Constitution, who was bringing a new squadron for action against the Barbary pirates. Nautilus sailed with Preble on 6 October to Tangier where the display of American naval strength induced the Europeans of Morocco to renew the treaty of 1786. Thereafter, Tripoli became the focus of Preble's attention.
Somers' service as commanding officer of Nautilus during operations against Tripoli won him promotion to master commandant on 18 May 1804. In the summer, he commanded a division of gunboats during five attacks on Tripoli.
On 4 September 1804, Somers assumed command of bomb ketch Intrepid which had been fitted out as a "floating volcano" to be sailed into Tripoli harbor and blown up in the midst of the corsair fleet close under the walls of the city. That night, she got underway into the harbor, but she exploded prematurely, killing Somers and his entire crew of volunteers.
Several ships of the US Navy have since been named USS Somers in his honor.