The United Nations Convention on the law of the Sea (UNCLOS) defines the Exclusive Economic Zone of a maritime nation as the area of sea adjacent and beyond the Territorial Sea up to 200nm from the coastline. Within the EEZ, the coastal state has rights of exploitation and management responsibility for all natural resources. Such resources have traditionally included the various marine living resources (fish, mammals, coral etc..) and mining operations (oil & gas, diamonds, dredged materials etc..). However, renewable energy sources are also being developed from wind, wave and tidal sources within the EEZ. Therefore, navigation within the EEZ is likely to mean that there are many more obstacles than in the past. The traditional approach of setting a course and allowing the ship to simply “drive” itself could result in disastrous consequences. Such consequences may involve damage to the ship or to an offshore structure or a vessel involved in fishing or mining activities. The on board ARPA radar has the ability to warn of targets ahead of the ship but warnings are sometimes not acknowledged.
Offshore VTS ?
Therefore, if ships may not respond to new obstacles that are being constructed with the EEZ, is it time for VTS to be established beyond its normal applications within the Ports, Straits and Traffic Separation Schemes? The objectives of ensuring Safety of Navigation, Unhindered Access and Environmental Protection would equally apply for an offshore VTS. For the owners of any offshore assets it would also provide asset protection. In the North Sea, Statoil of Norway has implemented an offshore VTS and was recently presented with an award for improving vessel safety within their area of operation. Other Oil Companies have Emergency Response Centres, but at present Statoil seems to be one of the few who actively manage shipping to reduce the risk of collisions with platforms.
In the offshore wind sector, the wind farm developers are using some VTS related technology to assist in managing their own vessels travelling to and from the wind farm and while operating on the wind farm. The UK Maritime & Coastguard agency guideline MGN371 (Annex 4) identifies a number of risk mitigation and safety measures that may be necessary (depending on the level of risk). These include the use of radar, AIS and CCTV surveillance, implementation of safety zones and routing measures within or near the wind farm and a continuous watch on multichannel VHF, including DSC (Digital Selective Calling). It could easily be concluded that this would comprise an offshore VTS.
Wider area Vessel Monitoring
A VTS is limited by the range of its sensors. Therefore for vessel monitoring across the EEZ a range of alternative sensors and tracking systems are required. AIS signals can be received by satellites in addition to their local area VHF ship to ship or ship to shore capability. Other wide area vessel monitoring techniques include Fisheries VMS (normally a position reporting, point to point satellite data communication link used by Fisheries Authorities) and LRIT (similar to VMS but delivered to National Data Centres through Application Service Providers).