Existing coastal observatories in European waters are composed of platforms such as moored buoys, piles, profiling systems, gliders, ';ferryboxes' and automated systems on board of ships of opportunity. JERICO project strives to integrate existing infrastructures and provides a platform for the identification and dissemination of best practices for the design, implementation, operation and maintenance of observing systems and the dissemination of data. In order to reach these objectives several kinds of actions are undertaken, amongst which the offer of Trans-National Access (TNA) to a number of coastal observatories and calibration facilities for international research and technology development. This presentation will give a short overview of the selected TNA proposals and a focus will be drawn on some of the TNA results. Calibrating sensors regularly is the prime requirement for getting reliable data from coastal observatories and ensuring their long-term relevance as viable providers of information on the marine environment. The calibration facilities at the HCMR complex in Crete hosted users for calibration experiments. The first one was accessed by a HCMR team to improve their experience in calibrating high-quality oceanographic temperature sensors using primary ITS-90 reference standards. The experiment involved full calibrations of two SBE 35 thermometers from Sea-Bird Electronics, Inc. owned by the HCMR that will be used as reference sensors for temperature measurements in their calibration laboratory in Crete. Gliders make oceanographic measurements traditionally collected by research vessels or moored instruments, but at a fraction of the costs. The GESEBB glider Mission started in July 2013, in the southeastern Bay of Biscay. The objective of the mission is sampling the characteristics of a mesoscale eddy that appears in the southeastern Bay of Biscay, during spring and summer. The origin of this structure is associated with the strength and extension of a winter warm flow on the cantabrian slope. Since this eddy is retained in the study area during months, it is expected that during Jul.-Aug. 2013 it will be close to the position observed in the previous figures Fixed platforms allow long term -sensor testing and -measurements. The presented experiment is led by CNRS/OBS-VLFR and consists in the implementation of automatic Dissolved Oxygen (DO) measurements in the mooring operated by CNR/ISMAR in the Corsica Channel (Ligurian Sea). The deployment began in Nov. 2012 and lasted for twelve months. The final purpose of the research is to integrate the DO concentration in the long term time series data in the Ligurian basin to track and evaluate the water mass variability and to estimate the time lag between the eastern and the western part of the Ligurian Sea. The development of high-quality and comprehensive coastal observing systems has only recently moved forward, principally at national and regional level. In this overall context, the JERICO project aims at creating a solid and transparent organization towards an operational service for the continuous and sustainable delivery of high quality environmental data and information products related to the marine environment in European coastal and shelf seas. It promotes joint research initiatives and standardisation as illustrated by TNA experiments.