The STM 500 is a Turkish mini submarine of the 500-tonne class under construction since 2022.
The shallow-water diesel-electric submarine is being built by Turkish defense company STM with completion of the first vessel not expected until 2026.
[1] As of June 2022[update], the customer for the project had not yet been publicly released.
[1] The STM-500 will displace approximately 500 tonnes, have a crew of 18, and be able to transport a squad of 6 special forces personnel.
It is being designed to have an endurance of 30 days and a maximum dive depth of 250 meters.