An area within which naval, military or aerial exercises are carried out also called an exercise area.

A specified area designated by an appropriate authority within which navigation is restricted in accordance with certain specified conditions.

A floating object moored to the seabed in a charted place as a navigation aid or for other specific purpose.

A tower or structure containing a beacon light to warn or guide ships.

A prominent specially constructed object forming a conspicuous mark as fixed aid to navigation.