Deep sea observatories

A survey of some deep-sea observatories that have either been deployed or h ave been developed is provided. The enabling technologies that facilitate t he powering, command and control and the transmission of data back to shore is discussed. To facilitate this discussion, examples of a number of obser vatories are categorized as "Wired to Shore", "Wired to Surface" or "Wirels ss". Among those observatories discussed are Japan's Hatsushimu. Real Time Long-term Deep Sea Floor Observatory, the Hawaii Undersea Geo-Observatory ( HUGO), the Hawaii 2 Observatory (H20), Ocean Net, the Geophysical and Ocean ographic Station for Abyssal Research (GEOSTAR) and the NEPTUNE Project. So me relative advantages of each approach are discussed as regards cost, tech nical and logistical considerations.