he cavernous Boathouse 4, in Portsmouth Historic Dockyard, is alive daily with the bustle, noise, smell and dirt of classic naval boats under repair and renovation: everything from small rowing gigs to admiral’s barges. In the quieter mezzanine above the workshop floor hangs a boat of great historical importance while, underneath her, a fully operational replica of her has just been completed. The hanging vessel is Coastal Motor Boat 4 in which, in 1919, Lieutenant Augustus Agar earned the Victoria Cross (VC). She has been much restored over the past 100 years and is now only a bare hull stripped of her engine and most of her equipment. The replica that has just been completed below CMB4 is a near-copy 40ft (12.2m) Coastal Motor Boat (CMB) launched in the summer of 2023. Gleaming in her white paintwork, she has undergone sea trials and a formal commissioning ceremony and is proving fully able to emulate the record-breaking speeds once achieved by her elder sister in 1916. These torpedo-carrying hydroplanes were designed by the famous shipbuilder John I Thornycroft Ltd in 1915 with the aim of skimming at great
