Technical Circular No:81/2018

Subject: Participation in The WMO Voluntary Observing Ships Scheme.

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  1. The International Maritime Organization (IMO) has recently issued a revised circular, 1/Circ.1293/Rev.1 dated 25th May 2018 (copy attached) Participation In The WMO Voluntary Observing Ships Scheme, which has revoked the original circular of the same title.
  1. The World Meteorological Organization (WMO) has requested IMO’s Maritime Safety Committee (MSC) to reintroduce the request for the recruitment of ships to provide ship-based marine meteorological and oceanographic observations. These ship-based meteorological reports provide vital real-time feedback on ocean weather conditions to weather forecasters who use the data to improve the quality of the forecasts and warnings issued through, for example, the Global Maritime Distress and Safety System (GMDSS) for mariners at sea.
  1. Furthermore, it should be noted that ship-based oceanographic measurements (e.g. Expendable Bathythermographs (XBTs)) also provide a valuable data source for studying the changes in climate which have become a matter of global concern in recent years. IMO and, in particular, its Marine Environment Protection Committee, are giving high priority to the work relating to the issue of climate change. Ships' meteorological observations are not only recognized as being essential for the provision of safety-related services for ships at sea, but also for ships' routeing, search and rescue, marine pollution prevention, and climate change studies (i.e. quantifying extreme weather events that can affect the maritime industry).
  1. Finally, it is noted that sometimes ship-based meteorological and oceanographic reports are the only data available from data-sparse areas such as the polar regions. While the real-time meteorological and oceanographic data collected on board ships is provided concerns regarding the for forecasting, climatology and research applications, some shipowners and masters have raised publication of ship identification and position data.
  1. WMO has, therefore, established a high-level dialogue, involving affected Members, IMO, ICS, shipping companies, relevant organizations and technical commissions, to propose a general and universally acceptable solution to the issue. This high-level dialogue resulted in schemes to mask ships' call signs. This solution will address shipowners' and masters' concerns as well as those of the WMO community regarding data monitoring and quality information feedback requirements. The continued participation of ships in providing marine meteorological and oceanographic observations remains critical.
  2. This message is being brought to the attention of shipowners, ship operators, ship managers, masters, and crews with a request to support the WMO/IOC (UNESCO's Intergovernmental Oceanographic Commission) marine meteorological and oceanographic observations and their National Meteorological Service (NMS), by offering their ships to participate in the WMO/IOC Marine observations programmes. More information can be located at the following web address:
  1. Shipowners, ship operators, ship managers and masters are requested to read the attached circular so as to understand the details of The Voluntary Observing Ships Scheme described in the Annex to the Circular. Included is the information required for a ship operator to join the program. Also included are two maps, one showing the areas of data observations in 2016, and the other showing the areas of recent XBT deployment. Voluntary participation in the ship-based marine meteorological and oceanographic observations programmes of WMO/IOC will help improve the quality of forecasts and warnings, as well as contributing to the enhancement of safety at sea.


  1. IMO Circular No. MSC.1/Circ.1293/Rev.1 dated 25th May 2018


This Technical Circular and the material contained in it is provided only for the purpose of supplying current information to the reader and not as an advice to be relied upon by any person. While we have taken utmost care to be as factual as possible, readers/ users are advised to verify the exact text and content of the Regulation from the original source/ issuing Authority.


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