The European Multidisciplinary Seafloor and water column Observatory (EMSO) is a research infrastructure distributed throughout Europe for seabed and water column observatories. It aims to further explore the oceans, better understand the phenomena that occur on the seabed, and elucidate the critical role that these phenomena play in global Earth systems. This observatory is based on observation sites (or nodes) that have been deployed in strategic locations in European seas, from the Arctic to the Atlantic, from the Mediterranean to the Black Sea. There are currently eleven deep water nodes plus four shallow water test nodes. EMSO Western Ligurian (EMSO-WL) is one of these permanent underwater observatories located in the Ligurian Sea and is deployed off Toulon, France. This region was chosen for its particular scientific interests such as: seismicity, topography, turbidity, biodiversity, water mass dynamics and organic matter flow. This underwater observation network is located close by KM3NeT (https://www.km3net.org/) which has a modular topology designed to connect up to 120 neutrino detection units. Earth and Sea Science (ESS) instrumentation at the EMSO-WL station is based on two complementary components: an instrumented interface module (MII) and an autonomous instrumented line (ALBATROSS) as well as a junction box (BJS). The BathyFamily is a package of innovative multi-instrumented platforms to observe the deep sea. BathyBot is an Internet Operated Vehicle (IOV) deployed from a landing station (BathyDock), and close to BathyReef a 3D-printed biomimetic colonizer.