What is the normal length of time for a British Nuclear Submarine on cruise/patrol

l suspect that this remains classified information. Beware the Official Secrets Act and the Regulating Branch!

3 months. Do not tell any one.

Between 3 & 6 months.

They very the length of missions for the reasons noted above. They do not want anyone to know just how long they can stay out to sea or how far they can go.

However, Britain just launched a new nuclear powered sub & information in the paper said it could function for 25 years without having to refuel its reactor. So assuming it makes oxygen & water, the limiting factor would be how much food can they cram on board. If they can grow some sort of tolerable food such as algae that can be mixed with regular food, they could stay out an incredibly long time. Or if they had some way of getting more food on board while out to sea, theoretically u could keep the sub out to sea for the full 25 years or until the crew gave out.

3 months for a boomer (ballistic missile submarine), as much as 9 months for a fast-attack, but it would have to make various stops for provisions. Nuclear submarines make all of their own oxygen, potable water and electricity, but they bring on food stores just like any other vessel. No, none of that is classified. Yes, a nuke sub can go about 15 years without refueling.

86-90Days,depends on nature of patrol,and if calling anywhere for liberty.