Below is a post by a friend I have never actually met, Przemyslaw Krajewski. We worked on a CIMSEC project in 2013. As you might have guest he is Polish and in fact lives in Poland. He is an avid skier. We had a short discussion about MARSUR after I published this very short post about its existence. I told him I felt we needed to know more about the system and asked if he could help. He very quickly came back with the post below.
Actually I see a need for international exchange of Maritime Domain Awareness data in several parts of the world. Europe is well along in developing the protocols and mechanisms for such a system. It is badly needed in West Africa, in Central and South America. the South China Sea, and probably numerous other locations. If the US Coast Guard could join this effort, an international standard might result.
Przemyslaw apologized for his English, but I think he did a fine job.
This post intention is to elaborate a bit more on what MARSUR is and how it works. Maritime Surveillance project is initiative of European Defense Agency, established in 2006 and aiming at
“Technical solution that allows dialog between European maritime information systems. Containing 19 Member States plus Norway, the project aims to improve the common “Recognized Maritime Picture” by facilitating exchange of operational maritime information and services such as ship positions, tracks, identification data, chat or images.” 
Beyond member states actually participate also EDA itself and EU Satellite Centre (EU SATCEN).
Twenty members sounds scary and indeed it intuitively shows level of complexity. Just to give broader picture or background. Europe consists of 46 states plus 2 de facto independent but as eastern border of geographical Europe are a bit fuzzy, some sources counts 50 countries. 26 of them are members of European Union (as 27th by some is counted in Asia) and 27 are NATO members…but these are not the same countries.
If we quote Carl von Clausewitz the most famous statement that war is the continuation of politics by other means, so how EU could have one army without common political goal?
As a consequence most of military cooperation in European Union focuses on procurement efficiency. Obvious obstacles to overcome are differing political objectives, technical standards, organizational solutions within national security establishemnts, legal issues individual to participating states, semantics and many others. All of this is nicely and elegantly hidden in two words „facilitating exchange”. On the other hand there is comparatively little controversies around the project as overwhelming need to act upon reliable information is common for all states and institution involved.
Using more technical language MARSUR is decentralized network linking national systems via VPN using common semantics applied in software called Marsure Exchange System or MEXS. MEXS represents local national hub fed with information voluntarily shared by governments or more specifically by governmental agencies. In theory it could fuse data from military and civilian institutions/agencies and make it public or limit to specific user community like naval, border control, fisheries and so on. As infromation provides ranges in sensitivity from public to secret, both distribution and level of commitment could differ from country to country. Common mechanism would be multilateral or bilateral agreement on government level.
System entered demonstration phase in October 2011 followed by MARSUR Live Phase using prototype software. While Basic Level obligatory for all participant relied on manual exchange of information, Advanced Level is automated and set in 2016 as a goal to pursue as fast as possible.
MARSUR doesn’t exist in vacuum and represent military layer for broader initiative called EU Common Information Sharing Environment (CISE) integrating member states systems related to customs, fisheries control, marine pollution, border control, law enforcement, maritime safety & security and finally defense. MEXS 3.0 which represent the latest upgrade aims exactly at linking as much as possible of security and defense related systems to general framework of CISE. In parallel exist also geographically focused and similar systems – SUCBAS  and SUCFIS, effect of cooperation of Baltic Sea states (except Russia) and between Finland and Sweden.
MARSUR begins to show some practical results. In May 2017 was used in support of Italian Navy and EUNAVFOR operation Sophia in Mediterranean. System has been installed both in Rome headquarter as well as a mobile component afloat. This year it was used in live demonstration of Ocean 2020 consortium of european technology businesses nad navies conducted in Mediterranean Sea with next exercise planned in Baltic Sea .
Other useful links: