A stolen Hood could produce an F3-like HMS St Vincent

What replacement would the Royal Navy build if Hood disappeared, and what might it be called?

He expects an F3-like fast capital ship rather than a third Nelson, probably named St Vincent.

The Royal Navy would not simply order a third Nelson if Hood vanished. The likely response is closer to an F3-style fast version of the Nelson concept, restoring the missing battlecruiser capability with a true fast capital ship. St Vincent is proposed as the name, drawn from the Royal Navy's major age-of-sail victories and commanders. A later joke in which Hood returns after thirteen years reinforces that a substantial replacement would already have been built during her absence.