Where emergency naval crews would come from

How could the Royal Navy rapidly find and train enough people to crew an expanded wartime fleet?

A strong reserve would provide the essential trained core, while new recruiting and specialist training would still require time.

Building additional escorts is only useful if the navy can crew them. The first requirement is a sufficiently large and current reserve whose members already possess naval knowledge and can return more quickly than new recruits can be trained. Emergency recruitment could widen the pool, but specialist preparation would still impose delay. Mobilization capacity therefore consists of people as well as yards and equipment.