The following is the entry for Sidney Colpoys Dacres in William O'Byrnes 1849 'Naval Biographical Dictionary'.
DACRES, K.L.H., K.R.G. (Captain, 1840.)Sidney Colpoys Dacres is son of Vice-Admiral the late Sir Rich. Dacres, G.C.H., by Miss Martha Phillips Mllligan; brother of Capt. R. I. Dacres, of the Royal Artillery; brother-in-law of Capt. Wm. Fairbrother Carroll, R.N., C.B.; and first-cousin of Rear-Admiral Jas. Rich. Dacres.
This officer entered the Navy 8 Feb. 1817; passed his examination in 1824; received his first commission 5 May, 1827; and was appointed, 18 Jan. 1828, to the Blonde 46, Capt. Edm. Lyons. In Oct. following he landed in command, with Lieut. Alfred Luckraft, of a party of seamen, and, by erecting batteries and otherwise, effectively co-operated with the French in reducing Morea Castle, the last hold of the Turks in the Peloponnesus. Obtaining a second promotal commission, 28 Aug. 1834, Capt. Dacres assumed command, 16 Aug. 1836, of the Salamander steamer; for the importance of his services in which vessel off the north coast of Spain in 1839-40, he was promoted to Post-rank on 1 Aug. in the latter year. He has since been on half-pay.
Capt. Dacres is a Knight of the Legion of Honour, and of the order of the Redeemer of Greece. He married, 1 Oct. 1840, Emma, daughter of D. Lambert, Esq., of Tavistock Square, London, and has issue.