This paper will introduce the work of IMCA, the International Marine Contractors Association.The aim is to provide an overview of IMCA, its membership and how it supports both its membership and the offshore industry as a whole through its various technical divisions.In addition, it will take the audience through some of the key technical documents produced by IMCA and how they can be utilised to support a clients marine operations.The presentation starts by looking at the structure and membership of IMCA and is followed by a closer look at the two common activities, Competence & Training and Safety, Environment & Legislation which impact on all areas of IMCAs guidance.The paper will then address all the various aspects of IMCA guidance for each of its technical divisions focussing on the core guidance in: diving, marine survey and ROV which are developed and reviewed in collaboration with industry world-wide.In addition it will specifically look two critical documents which form the key for safe efficient marine and diving operations.