Very cautiously, Jack walks up to the bulkhead door. There's a little bit of warping and spurting, like any good Rapture door hit by the full fury of the sea, but otherwise it holds firm and true. And for all Jack knows, it was closed and sealed when they first crashed.

If Sinclair's behind that thing, he isn't getting rescued.

Like the sea before it, the full failure of the situation crashes in on Jack. He decided to get them both out. He was making it work. They made a plan of what to do when they reached the surface. And now... are they on the surface?

No. They're still in this fucking fish tank. Sinclair's probably dead. It's a complete failure. A complete failure to escape. A complete failure to affect his own future.

Jack takes out his pipe wrench, goes to a wall perpendicular to the bulkhead door, and begins to smash the shit out of it.