“The largest part of the NKN consists of small combatants, including torpedo boats, patrol boats, patrol craft, fast attack craft, and small amphibious landing craft. Of the approximately 200 torpedo boats, nearly half are DPRK-built. Most are equipped with 25 mm to 37 mm guns.”
google North Korean Navy
Their torpedo boats are somewhat similar to our PT boats of WW2 fame - fast & manueverable.
Sorry, I posted too fast. I thought it said a North Korean ship had maybe been torpedoed.
South Korean ship, entirely possible.