As powered ships came into use, the term was applied to the same approximate area of the ship (although the officers stations were moved to the bridge). It came to be applied to the area at the stern of the ship, sometimes a separate stepped deck, often used for secondary weapons and (on battleships) seaplane catapults. In modern designs the stern has been roofed over by the helicopter deck but a large space remains underneath which is typically used for sonar equipment and small boats and which is still referred to as the quarterdeck in Commonwealth navies.