What is Vos?

Ocean-going vessels share a longstanding tradition of communicating observation data on the marine environment. When merchant vessel observations started as an organized activity in the middle of the 19th century, observations were initially geared primarily to safety on the high seas. At present, however, the World Meteorological Organization (WMO) has institutionalized international communication of observation data by fleets of signatory countries. A huge amount of data has been collected from commercial vessels on such subjects as air temperature, air pressure, surface temperature, wind direction, and wind velocity. This information has proved of great value in many analytical procedures, such as studies of substances in, and energy flow between, the ocean and the atmosphere. While accurate meteorological data, as required for vessel operations, are readily available throughout the world, the importance of observations by ordinary vessels in clarifying the role of the ocean vis-a-vis global climatic changes, such as global warming, is being reevaluated.
Vessels providing this service are also known as Ships-of-Opportunity (SOO). A program of water temperature measurementCbased on the use of expendable bathythermographs, as promoted jointly by the UNESCO Intergovernmental Oceanographic Commission (IOC) and the WMO, is called the Ship-of-Opportunity Programme(SOOP), but its conceptual aim is identical to that of Vos (Voluntary Observing Ships).

Vos capabilities, however, are not limited to oceanographic and meteorological observations on the high seas. Vessels sailing coastal waters that are strongly affected by the adjoining land also contribute in a major way to studies on the degree of such influence. For example, at Japan's National Institute for Environmental Studies, marine environmental monitoring activities have been carried out since 1991, using ferries as Vos, targeted at Japan's coastal and adjacent seas as waters easily influenced by human activity. In Europe as well, at the Finnish Institute of Marine Research, for example, observations have been conducted since 1992 on such subjects as chlorophyll content and phytoplankton species, via ferries crossing the Baltic Sea. This activity is gradually leading to the development of pan-European monitoring programs on the oceanographic environment, such as 'the Ferry-Box' programme, using ferries that ply European coastal waters.