 They were designed to be rowed (with 18 oars) as well as sailed, for which purpose they carried a brig rig, though it was originally planned to rig them as schooners or brigantines.The initial plan was that they would mount a main armament of 4-pounder long guns, but this was rapidly substituted by a broadside battery of ten 18-pounder carronades, with two 24-pounders as chase guns in the bow and two 4-pounders as chase guns in the stern.The 4-pounders were soon deleted, making them all 12-gun vessels.