DIMDEX 2026: Both M23's C- and T-series mini-submarines operationally deployed

A 1:5 scale model of M23's C-Series mini-submarine, usually 22 m long, displayed at DIMDEX in January 2026. (Janes/Tom Barton)

Italian submarine-maker M23 revealed details of two mini-submarine types at the DIMDEX 2026 show held in Doha from 19 to 22 January, adding that both types were in operational service.

The design impetus for both the 22 m C-Series and 10.5 m T-Series mini-submarines came from special operations forces (SOF) possibilities, but also the intelligence, surveillance, and reconnaissance (ISR) capabilities such a platform offered, Romano Ricca, M23 chief sales officer, told Janes .

They are also valuable for operations in shallow waters, or protecting critical undersea infrastructure (CUI), Ricca said, adding that the C-Series has replicated smaller versions of most of the capabilities of a full-sized submarine.

The T-Series submarine has a maximum operating depth of 100 m, an underwater maximum speed of 7 kt, an underwater cruising speed of 4.5 kt, and a surface/submerged displacement of 17.25/18 tonnes. It has a beam of 1.95 m, a pressure hull diameter of 1.60 m, and a pressure hull length of 9.20 m. It has an overall height of 2.30 m, a main electric motor power of 18 kW, and an electric power capacity of 197 kW h. It has a range of 60 nm, with two crew (one pilot and one navigator), and can carry up to four divers. Up to four personnel can be in the lock-in/lock-out (LIO) chamber during operations, according to M23.