Continuous At Sea Deterrent

For 24 hours a day, 365 days a year, Royal Navy Vanguard-class submarines patrol the world’s oceans. Their mission? To carry the Trident missile system: the United Kingdom’s strategic nuclear deterrent.


Vanguard class at a glance


Total range

25+ knots

Top speed

15,900 tonnes

Total displacement

150 metres

Overall length

What are we doing?

Today, the United Kingdom’s strategic nuclear deterrent is provided by the Vanguard-class nuclear-powered ballistic missile submarine.

Together, these four boats – HMS Vanguard, HMS Victorious, HMS Vigilant and HMS Vengeance – patrol the world’s oceans, silent, undetected and ready to strike at any time. Their very presence sends a powerful message to those who would do us harm.

The first of her class, HMS Vanguard was launched in 1993 and now forms the cornerstone of the United Kingdom’s defence policy. She and her sister vessels contribute significantly to the Alliance’s deterrent forces.

A new class of ballistic submarine –the Dreadnought class – is currently under construction and is expected to replace the Vanguard-class by the 2030s, ushering in a new era of at-sea deterrence.