ISOM was founded in 1986 andisan informal network of managers of ocean-going research vessels. They meet once a year for meetings lasting 2–3 days, hosted by participating countries. The meeting sites are selected to alternate between a European country and non-European countries, since most members are from Europe and to spread the cost and time of travel for members around the world. Between meetings, the members are in contact via e-mail, telephone and the ISOM web portal (web reference 1).

Since there are only a few operators of ocean-going research vessels in each country at most, the ISOM network is often the only forum they have for discussing subjects and solving problems of mutual interest. ISOM currently has more than 80 members from 27 countries spread around the globe. Attendance at the annual meetings is usually between 30 and 40 persons.
Typical topics at the annual meetings are new vessel projects, new instrumentation, best practices for operation of research vessels and instruments and equipment. Lessons learned from science are also of interest to the group.
Regarding hydrographic instruments and equipment, multibeam echosounders is a hot topic for this group since many of the ocean-going research vessels are equipped with such equipment. The most common challenge is the ‘bubble sweep down’ problem. This is air bubbles generated by the bow section of the vessel when operating in heavy waves, which travel under the transducers and dampen the signal being transmitted and received. Different vessels are designed with different hull shapes, bulb forms and sizes, different mounting of the transducers (hull mounted or in a gondola under the hull) and with different use of tunnel thrusters in the bow area. So far, no one has been able to fully understand, model and predict thebubble flow under the hull, so every ISOM member involved in the design of new research vessels with multi-beam echosounders is very interested in new ideas and good results from echosounders and bubble sweep down.

An area of particular interest is techniques to reduce the underwater radiated noise from the vessel in order to give the echosounders the best possible signal/noise ratio. This involves different ways of reducing and/or damping vibrations caused by diesel engines, pumps, rotating machinery and fluid and exhaust pipes.

Some of the research vessels are built for operations in the Arctic and the Antarctic, and combining ice-breaking capabilities with hydrographic survey instruments mounted under and in the hull creates some very special challenges which few vessel operators outside ISOM have any experience of. The design of ice-going vessels with multibeam echosounders and other hull-mounted instruments is therefore expected to be an important topic of future ISOM meetings.

Another focus is the best possible utilisation of vessels, personnel and equipment. The ISOM forum is ideal for establishing contacts between different research vessel operators, in order to arrange loan or lease agreements for vessel time, equipment and/or personnel. The Ocean Facilities Exchange Group (OFEG), a barter system for Germany, France, UK, Netherlands, Spain and Norway, is another result of the ISOM meetings.
The European Research Vessel Operator (ERVO) group (web reference 2), which was established in 1999 to focus on regional and coastal research vessels in Europe, is another ‘offspring’ of ISOM. Another important meeting place for research vessel operators is the Research Vessel Operators Committee (RVOC), sponsored by the US University-National Oceanographic Laboratory System (UNOLS). Both ERVO and RVOC are in close cooperation with the ISOM.

Research vessel operators are therefore well organised, sharing knowledge and expertise. The operators also cooperate in order to maximise the return on investment made every year by governments around the globe in marine research vessels, instruments and equipment to support marine science projects.