Roughly 650 Fairmile Bs entered the wartime story, but no single completed total is entirely secure. Published counts range from about 645 to 660 because some yards continued construction when the need was obvious and no replacement order had arrived. One operationally important boat may have been built before its yard received a formal order and perhaps even without traceable payment. Britain's distributed small-yard capacity could turn standardised plans into ships faster than centralised paperwork could always record them.
Chapter · 45:05-47:43
Fairmile B mass production beyond the paperwork
Fairmile B output was so decentralized that yards sometimes continued building in anticipation of orders, leaving the exact wartime total uncertain.