How long can a nuclear sub stay underwater?

Nuclear submarines can stay underwater for extended periods, typically for several months, depending on factors like food supplies and crew endurance. They are powered by nuclear reactors, which provide a virtually limitless source of energy, allowing them to operate submerged without needing to surface for air. However, practical limits are imposed by crew provisions and maintenance needs. Generally, they can remain submerged for about 3 to 6 months before needing to resurface.