Charmian II was an express cruiser owned by C. Huges Manly of Baltimore built in Annapolis, Maryland by Chance Marine Construction Company and in September 1915 thought by boating observers after trials to be perhaps the fastest cruiser in her class in the United States.

[1][3] The cruiser is noted as one of the vessels assigned official numbers and signals by the Department of Commerce, Bureau of Navigation for the week ended June 5, 1915.

Various speeds are mentioned, in both miles per hour and knots with sources agreeing on a top speed of 28 kn (32 mph; 52 km/h),[1][2][3][6] The 11 ft (3.4 m) beam cruiser accommodated five people for extended cruises with a double stateroom and toilet forward of the bridge and a storage are and aft of the chain locker in the bow.

Manly and the cruiser are shown as running and winning the 368.5 nmi (424.1 mi; 682.5 km) Baltimore to Camden race in 1915.

The cruiser was assigned to the 2nd Naval District in southern New England, Charmian II served on patrol duty for the rest of World War I.