The Western Ionian Sea (WIS) is located in the central Mediterranean basin, Eastern Sicily Island (Southern Italy), Catania. The submarine site is operated by an electro-optical submarine cable located respectively 28 km off shore Catania at 2100 m depth. The infrastructure is a Regional Facility of EMSO ERIC.

The WIS is located in an area prone to numerous natural hazard issues due to high seismicity and the presence of Etna Volcano. The area is strategically relevant also for the oceanographic circulation between the Eastern and Western Mediterranean Sea through the Messina Strait and the Sicily Channel. The WIS facility is based on marine infrastructure built on an underwater electro-optical cable offshore Catania hosting seismic, geophysical and oceanographic sensors.

The land station may host devices (e.g. iDAS) which can be connected to the underwater optical fibers for measurements along the cable.