8 hours at 2 knots (3.7 km/h; 2.3 mph); 120 hours in emergency with only 2 pilots on-board
600 m (2,000 ft) (operating); +900 m (3,000 ft) (collapse depth)
Sensors and processing systems
Echo-sounder ELAC LAZ-100
pressure hull was made of HY-80 steel
MSM-1 USEL (Unità di Soccorso E Lavoro - Rescue and Work Vessel) was a deep-submergence rescue vehicle (DSRV) that was rated to dive up to 600 m (1,969 ft). It was built by Cantieri Navali Ernesto Breda/Fincantieri for the Marina Militare. The sub was capable of descending to 600 metres (2,000 ft) below the surface and could carry 8 passengers at a time in addition to her crew. MSM-1 USEL was hosted by mother shipAnteo at La Spezia from 1980 to 2002. That year MSM-1 USEL was replaced by the DRASS Galeazzi SRV-300.
MSM-1 USEL was the first submersible vehicle for underwater research and work of completely Italian conception. The basic design of MSM-1 USEL was done by ESCO of Milan. The pressure hull is made of HY-80 steel and subdivided in two compartments: a cylinder with hemispherical ends located aft, and a sphere forward, interconnected by a cylindrical tunnel. The afterbody is tapered and finishes with the propeller cone. Aft stability planes, two vertical and two horizontal, are arranged forward of the propeller.
MSM-1 was updated (MLU - MidLife Update) in 1989 by MARITALIA of Fiumicino. Work took a year to complete and the vessel was renamed MSM-1S USEL. The DSRV's maximum depth was established near Cinqueterre (La Spezia) at 480 m (1,575 ft).
Since 8 September 2015 MSM-1S USEL has been held by the Museo Tecnico Navale (Naval Technical Museum)  of La Spezia and now is preserved for the public.
^"A Bordo Dell' Anteo". Betasom - XI Gruppo Sommergibili Atlantici.
^"Naval Technical Museum La Spezia - Marina Militare". www.marina.difesa.it.