Vosper offered the Royal Navy a succession of motor torpedo boat designs rather than one standardised 70-foot type. Its 45-foot private-venture boats were judged too poor in seakeeping for combat but still found useful employment, while the 60-foot design grew from RAF high-speed air-sea-rescue launches and carried 18-inch torpedoes at about 33 knots. The 70-foot family returned to the classic torpedo-boat emphasis of 21-inch torpedoes, depth charges, machine guns, and light cannon on a fast hull. At one point the Royal Navy may have had six different Vosper MTB types in service. Their widely separated hull-number blocks made actual British strength difficult for opponents to infer. A large industrial base could keep producing and redistributing small craft in ways that made operational sightings a poor guide to total numbers.
Notable Point · 38:11-42:43
Vosper MTBs and the fog of small-craft numbers
Vosper's varied MTB designs ranged from short private-venture craft to 70-foot torpedo boats, while dispersed numbering made British strength difficult to estimate.