A submarine (or simply sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term most commonly refers to a large, crewed vessel. Modern nuclear submarines can last for 25 years without needing refuelling because they use a nuclear reactor. If you manage to get hold of a nuclear submarine during the zombie apocalypse, you can last for years, provided that you have dozens of nuclear propulsion technicians, radar and sonar operators, steam propulsion specialists, and dozens of other crew with years of training.
Pros
- Can last for 25 years without needing refuelling.
- Zombies can't get you in the middle of the sea.
- It will be very hard for other survivors to raid you.
- Has torpedoes, in case you need to destroy a enemy ship, though firing one and hitting a target requires nearly two dozen crew working together.
Cons
- Can last for 90 days without needing additional supplies.
- Very hard to get hold of one.
- Requires dozens or hundreds of crew to operate.
- Needs to be restocked with food and like ships, there isn't enough room to farm crops or raise animals.