'My top-secret trip aboard one of the UK's Vanguard submarines - here's what it's like'

'My top-secret trip aboard one of the UK's Vanguard submarines - here's what it's like'The Mirror was given the rare chance to accompany Prime Minister Keir Starmer to board a submarine on "Day Zero", its return to UK waters after a record 206-day deploymentCommentsNewsopinionLizzy Buchan Political Editor12:00, 19 Apr 2026Updated 12:10, 19 Apr 2026View 5 ImagesKeir Starmer meets the crew on board a Vanguard Class submarine(Image: Simon Dawson / No 10 Downing Street)The whereabouts of Britain's nuclear-armed submarines are one of the nation's most closely guarded secrets.‌One of the four Vanguard-Class submarines that carry Britain's nuclear deterrent continuously patrols the seas, ready to fire Trident missiles on the Prime Minister's command.‌Only four people aboard know its route, and its location is kept secret for the length of its deployment.‌It stays silent as it makes its slow, stealthy passage deep beneath the waves, receiving only incoming communications to allow it to stay hidden from hostile powers.The Mirror was given the rare chance to accompany the Prime Minister to board a submarine on "Day Zero", its return to UK waters after a record 206-day deployment.READ MORE: Keir Starmer warns UK must not take eyes off Putin from top-secret Vanguard sub visitREAD MORE: Inside UK's four Vanguard-Class submarine - including £6billion underwater nuclear monsterView 5 ImagesKeir Starmer and Mirror's Lizzy Buchan alongside the Vanguard-Class submarine(Image: Simon Dawson / No 10 Downing Street)‌The trip was so secret that I referred to it only as "story X" in advance. Just a few colleagues knew where I was going.In the early hours of the morning, I joined the PM on a choppy boat ride through the pitch dark to board the vessel, which we have agreed not to name for security reasons.As the sun rose over the Scottish coastline, the surfaced vessel suddenly loomed into view, its hulking...