The aim of the extension of COST Project 43 is to complete Phase II of the original project plan which was set up an experimental European Network of Ocean Stations (ENOS) and taking into account the interest shown by the users, form an opinion on the extent and progress of the integration of the experimental network into an operational and standardized network covering the whole of the European region. Experimental works on evaluation, testing and further development of existing components such as sensors, structures and transmission systems carried out under COST 43 will be continued.