The Sea is the medium that allowed people to travel from one continent to another using vessels and even today despite the use of aircraft. It has been acting also as a great reservoir and source of foods for all living beings. However, for many generations it served as a landfill for depositing conventional and nuclear wastes, especially in its deep seabeds and there is a race to exploit minerals and resources, different from foods, encompassed in it. Its heath is a very challenge for the survival of all humanity since it is one the most important environmental components targeted by the global warming: Tsunami and El Niño are consequences and indicators of bad development. As everyone may know, measuring is a step that allows major knowledge of a phenomenon or an asset. That is why METROSEA will serve as a forum for presenting recent advances in the field of measurement and instrumentation to be applied for the increasing of our knowledge for protecting and preserving the Sea.