Bottom geophysical observatories: methods of designing and area of application

New tendencies of Global Ocean study with the help of multi-purpose autonomous bottom observatories are considered. The brief review of a history of creation and use of these devices is resulted. Features of their design and a scope are analyzed. Concrete examples of use of bottom observatories for studying forerunners of strong sea earthquakes and a tsunami and ecological monitoring of industrially mastered water areas are described.