Coastal Motor Boats

According to conventional naval history, the Coastal Motor Boat was the brainchild of three enterprising young Royal Navy officers in the early stages of the First World War. This new book reveals that the truth was far more complex, and historically more significant. Research in previously unused family records shows that the shipbuilder John I Thornycroft played a pivotal role, building on his pre-war experience in the new sport of fast motor-boat racing, without which the technologically advanced CMB could never have been built.

This book goes on to analyse the original role for which these boats were specifically designed – an attack on the German High Seas Fleet in its protected anchorages – and why the operation never took place. Later activities are covered but by the end of the war many regarded the CMB as a disappointment, if not a downright failure. This changed dramatically in 1919 with the RN’s intervention against the Bolsheviks, when CMBs spectacularly raided the Kronstad naval base following the single-handed sinking of the Russian cruiser Oleg by CMB.4. Although these operations have been written up many times previously, for the first time this book has had access to contemporary Soviet reports which throw much new light on these events and their significance.

After the war, the Royal Navy lost interest in CMBs – unlike the Soviets who built large numbers of what were effectively copies – but the Thornycroft design continued to be built and operated by navies as far apart as those of Finland and China. Some of these saw action in the Second World War and these largely unreported actions are also covered.

The story concludes with a description of the current project in Portsmouth Naval Base which aimed to build an exact replica of CMB.4. The information gleaned from this ‘experimental archaeology’ forms a fitting end to a book replete with new information and novel insights.