“NK subs are crap, like converted LP tanks with outboard motors.”
60’ long with a crew of 20. How big is your LP tank?
One of these sank a S Korean warship several years ago totally undetected. They carry Russian homing torpedoes with a 600 pound explosive charge.
Yup, junk, and no threat./s
Small subs benefit from shallow waters and they have a shallow sea. Wise investment.