The Highflyer-class cruisers were essentially repeats of the previous Eclipse class, albeit with a more powerful armament and propulsion machinery.

The engines were designed to produce a total of 10,000 indicated horsepower (7,500 kW) which was intended to give a maximum speed of 20 knots (37 km/h; 23 mph).

The ships easily exceeded their designed power and speeds during their sea trials.

[2] The main armament of the Highflyer class consisted of 11 quick-firing (QF) 6-inch (152 mm) Mk I guns.

[1] The ships' protective deck armour ranged in thickness from 1.5 to 3 inches (38 to 76 mm).