Nahang-class submarine

The Nahang () is an Iranian-made class of midget submarine designed for shallow water operations. Only one prototype of this class is known to be completed, although its characteristics have remained unclear.
History.
Iran had shown interest in midget submarines in the 1980s. According to the "Conway's All The World's Fighting Ships", Iran assembled a midget in Bandar Abbas that was completed in 1987 in an unsuccessful attempt. Iran reportedly purchased a second midget of another design from North Korea, delivered in 1988. It is alleged that by 1993, nine midget submarines –able to displace 76 tons surfaced and 90 tons submerged, with a top speed between and – were imported from North Korea.
Existence of "Nahang" was first known in April 2006. On 6 March 2006, Iranian state television announced that "Nahang 1" has been commissioned into the Southern Fleet. Later that year in late August, she participated in the third phase of Zarbat-e Zolfaghar wargame.
Two other submarines in the class were allegedly planned, but building further units is considered unlikely.
In April 2017, Bellingcat reported that for the first time in years, satellite imagery suggests "Nahang" had been deployed for a mission.
Description.
There is not much confidently known about characteristics of the class. According to "Jane's Fighting Ships", the class displaces when at the surface and while submerged. Alternate estimates for surfaced and submerged displacement are and respectively while the number given goes as high as .
"Jane's" mentions the approximate dimensions as for length, with a beam of and a draft of . and are top speeds reported for the submarine. "Nahang" is reportedly unarmed and not fitted with torpedoes, however there are contradicting reports suggesting it has a pair of 533mm torpedo tubes in drop collars and can carry and lay four MDM-6 or EM-52 naval mines. "Nahang" may be utilized as a mothership for swimmer delivery vehicles and a platform for special operations.
The submarine has no sonar on the report of "Jane's", but another account suggests that she is equipped with active/passive sonar on her bow. The machinery installed for propulsion is unknown. Other apparatus reportedly installed include a mast with electronic warfare support capabilities (similar to Russian-made 'Stop Light' type) and surface search and navigation radar.