Bumping into (not literally) a Soviet nuclear sub with serious reactor trouble. It happens all the time.
This could present lots of story options. Do the glowing Soviet submariners just want a ride? Do they try to take over the ship? Does the crew dare help them? What if they don't? Could be interesting.
Mutiny. That's what NPCs are for.
Any "Lost" fans out there? The island
used to be in the South Pacific somewhere. Probably a bit too metaphysical for most T2K campaigns.