How the Royal Navy sustains long deployments

What are the Royal Navy's longest deployments?

Vanguard-class submarine patrols are among the longest individual deployments, while major carrier-group voyages last many months and forward OPVs extend hull deployments by rotating small crews overseas.

Ballistic-missile submarines produce exceptionally long continuous patrols, while carrier groups undertake major global deployments with escorts and auxiliaries. Smaller OPVs can remain forward even longer because their crews are practical to rotate overseas. That method does not scale easily to a carrier with thousands of personnel, so platform size changes the meaning of endurance.