The Saratoga (CV-3) was capable of 33 knots. Only the Iowa Class of battleships were capable of keeping up with the carrier fleet.
http://en.wikipedia.org/wiki/USS_Saratoga_(CV-3)
The first carriers were battleships WITHOUT their fighting superstructure. No? No big guns, no massive belt and deck armour, would result in a lighter ship with the same power plants. Add planes and support materiel, it probably still results in a lighter OAW. No wonder they were faster.
The Iowa class ships were all the more impressive.