Fifty North Korean Submarines Deployed at once.

[seaman hornsby]

http://asia.nikkei.com/Politics-Economy/International-Relations/North-Korea-plays-a-dangerous-game-with-latest-military-tactic

[Covert Shores]

This event was a wake up call, and something of an impressive achievement for the North Korean navy. Even if some were towed out of harbor (which would be a legit tactical choice for some of the smaller boats anyway) or sat off their home base, it's still surprising that they could muster so many crews etc. Their readiness levels are some distance south of 70% ordinarily. Their fleet types:

1 SSB
Old Whiskey and Romeo boats
40m sang-o-2 boats - latest design of attack sub
35m sang-o boats - both attack and ISR /SF versions
29m yono boats - attack type
24m p4 'yugo' boats - attack and ISR / SF versions, older now
18-20m yugo boats - may all be out of service.
Submersible and/or semi-submersible Infiltration landing craft


They also have two recent corvettes with at least one more building, plus various VSV (Very Slender Vessel) infiltration craft.

The most recent fresh info is confirmation that they operate the 'Tir' low observable torpedo boats. It was known that they built them for export, but this is the first hard evidence that they operate them.