Strongly constructed for possible wartime use, the Georgiana III was also noteworthy for its diesel power plant. Nearly all yachts of this and earlier periods had steam engines but diesel allowed for efficient operation with much smaller crews. Powered by a 240 hp Southwark-Harris Diesel sporting four nine-inch diameter cylinders with a 13-inch stroke, Georgiana III's engine could be fully reversed in only five seconds. Moreover, the engine could be brought to full power, from a cold start, in just ten seconds-a considerable improvement over the time required to bring a contemporary steam engine to full power. Compressed air started the engine, a process that could be carried out fifty times on a single charge of the air bottles. Steaming at 15 mph, Georgiana III consumed eight gallons of fuel an hour and had a cruising range of 2,000 miles. This is excellent fuel economy, even by current standards. The vessel's fuel tanks held 1,070 gallons of diesel oil. Colonel Morse would later install a diesel engine from his own company, a Fairbanks-Morse Model 35. 

The Rosinco as it appeared under its second name, the Whitemarsh

Well-appointed above and below decks, the ship would have impressed the casual observer with its refined accommodations. The main salon, with watertight doors at both ends, was paneled in quartered oak. Overhead were brown oak deck beams and cream white ceiling panels. Furniture upholstery and wall panels consisted of English tapestry, and The Motor Boat magazine noted that the carpet possessed ".a design and color harmonizing with the brown oak." Three built-in sofa beds, a Pullman bed, quartered oak furniture, an eight-person dining table, and two sideboards could accommodate several guests. Cabinet and sideboard doors were glazed with leaded glass.