Data collection and management, marine research infrastructures, and capacity building are fundamental to ensure that Europe benefit from knowledge and innovations possible with marine and maritime research. Over the last years, many initiatives have been launched to better coordinate the marine research infrastructures’ development and use at EU level with the aim to create sustainable cost-efficiency in marine and maritime data collection and management, use of the different research infrastructures, provision of appropriate capacity building services, supporting models for knowledge-based policy-decisions and development of the maritime economy. However, in Europe these initiatives have traditionally been fragmented leading to overlaps and duplication of efforts while important gaps are left unattended. The overall aim of work package 6 of CSA Oceans is to draft optional solutions to overcome some of the major gaps, needs and bottlenecks related to marine research infrastructures, observations/data collection, human resources and capacity building. This will allow identification of where JPI Oceans can add value by providing a gaps and needs analysis as input to the development of the Strategic Research and Innovation Agenda (SRIA). As a first step, WP6 has integrated mapping efforts conducted over the last years into one single repository, gathering all information on infrastructures related to marine and maritime research activities. This repository, developed in cooperation with EUROCEAN, will ensure the storage on a long-term perspective of all this information. As part of this mapping exercise, a broad stakeholders and public consultation was conducted in cooperation with WP3, WP4 and WP5 in order to collect input on potential needs/actions/tools to achieve the JPI Oceans goals. Building on this mapping exercise, as well as on other existing initiatives (EURO-Argo, EMSO, EuroGOOS, EUROFLEETS, SEADATANET, JERICO, EuroSites, MyOcean, EMODNET, WISE Marine, Euromarine, SEAS-ERA etc.), WP6 conducted a preliminary analysis of marine research infrastructures and human capacity building. This preliminary analysis should be seen as an introduction to the needs and gaps analysis which will be delivered in a second phase of the project (Deliverable D6.2) in order to develop the SRIA of JPI Oceans. The objective of this document is to report on the first phase of the project: the mapping and preliminary analysis of marine research infrastructures and human capacity building. Chapter 2 is dedicated to the work package methodology, Chapter 3 to the mapping a preliminary analysis of marine research infrastructures including a presentation of the repository and Chapter 4 to the mapping and preliminary analysis of marine human capacity building including a case study.