So, here we go.

There was a foreign submarine off the coast of CA... they seemed Russian. There was another sub chasing them... or... a huge sea-monster... that fact kept switching. It was decided that the only way to escape was to make a dash for land and hide against the side of an underwater shelf. The only problem was that this shelf was in the San Francisco bay and, them being an enemy submarine and all, if they were caught they'd be jumping into all kinds of shit.

However, things being what they were, they decided to make a go of it. The idea was that the sub/monster wouldn't be able to detect them anymore and would give up and go away.

This is where it shifted into video game format. The sub was up against the shelf and the sub/monster was right next to it... waiting. The Captain was in a room talking with the Commander. The crew had been acting strangely... responding to common statements with anger and paranoia. The Captain was saying that he was reducing various charges against the crew because it was clear that something was going on. I remember hearing the word, "mutiny." The Commander suddenly screamed, "Are you accusing me of something?!"

The Captain/I was shocked at his response and tried to explain what was happening, but the Commander kept getting more and more upset, screaming curses and obscenities before finally running from the room.

The dream skipped here and I was watching as a blob of a monster chased crewmen around the sub and [very graphically] killed them and ate bits of their skin. It was rather unsettling, so I turned my head as it caught a woman.

Then, the dream skipped again and I was controlling another woman crewman. She was running from the monster and was trapped against a railing. The dream skipped yet again and I was the woman. The monster tried to grab me, but I dodged and it only clawed/bit my arm.

...and I woke up.