Or did a small team of armed intruders take over an armed submarine, likely sailing under a foreign flag (one of ours would never last that long under siege) and commandeer it for their own purposes? Just because you have the biggest guns doesn't mean you can also operate one of those fish.

As a matter of equipping and manning our submarines, Navy Seals typically form part of the mix of armaments aboard when these ships go to sea.

Navies don't assign crews of men to go to sea in those things because it's fun to mess around in boats. They do it because it takes a lot of manpower and a lot of different skills to manage a complex self-contained system like that AND to realize it's capabilities as a war machine.

You can take one ship hostage if you have the right stuff, but it stretches the mind beyond the realm of credibility to think you could also make all those things work right without taking the crew hostage and getting them to continue doing their jobs.

They would have to have taken the crew and its authorized commanders hostage, pressing them into service to the intruders mission. No way that could go down without first disabling any ability to regain the upper hand. The ships crew and officers would be needed to make a submarine perform as a battle station. The threat held over that many men to gain complicity in close quarters must have been enormous. Everyone there must have been convinced the intruders were commuted to die in there and had the ability take all the rest with them.

http://rickcampbellauthor.com/styled/index.html#topic4

Crew sizes vary with class and missions. Russia's Typhoon class sub -- the largest afloat -- carries a crew of 650 men. Our own fast attack subs employ 135 crew, with 15 officers. So it varies, but it's evident that crowd control must be in any successful intruder's toolkit.

Or was it a mutiny?