Military technology is reaching a whole new level – one of the latest developments in naval technology is the launching of the HMS Audacious, a new British nuclear submarine which is only one of seven subs of the Astute class. These subs are designed with nuclear engines with enough power to power a small city, and they will also not need refueling for at least 25 years. They are subbing in (pun intended) for the older Swiftsure and Trafalgar classes which will be completely removed from the British navy in the coming years. These subs are the quietest in the world too, but their capabilities speak loudly enough.
Namely, they have the option to be submerged for 25 years straight because they have gadgets on there that create oxygen by separating water and they also desalinate water from the oceans for drinking and hygienic purposes. They can remove carbon dioxide from their air as well as store enough food for the crew. However, these subs can only store 3 months worth of food and apart from crew fatigue that is the only thing holding this British nuclear submarine back from diving in the ocean and surfacing again in a different era.