In March HMS Vengeance returned to Faslane from a patrol that began in late August. Lasting six months, two weeks, and three days, the patrol is thought to be the second longest on record. The patrol followed a 195-day patrol from HMS Vigilant, which ended in early September. According to the Navy Lookout website, the longest patrol on record was a 207 day patrol carried out by HMS Victorious in 2021.
The recent series of long patrols is a consequence of the age of the Vanguard fleet and the repairs required to make the submarines ready to go to sea. Since HMS Victorious arrived in Devonport for deep maintenance in May 2023 and HMS Vanguard had not returned to surface after its deep maintenance period, only two submarines have been available to patrol for nearly a year. HMS Vanguard returned to Faslane later in March, having returned from the US following its unsuccessful test-firing.
When stories about the current long patrols first appeared in the press, concerns were raised about the impact upon both crews and submarines. If HMS Vanguard is now ready to begin patrols that will ease some of the pressure on the other submarines. However, as HMS Vengeance and HMS Vigilant will need to remain in service for many more years, and there have been delays in moving HMS Victorious into dry dock in Devonport, any respite is likely to be temporary.