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About Boathouse 4


Boathouse 4 is a free attraction at Portsmouth Historic Dockyard, combining an exciting interactive exhibition, traditional boatbuilding training and a brasserie overlooking the harbour, all under one roof.


The Boathouse, now managed by Portsmouth Naval Base Property Trust, was restored and opened to the public with support from the Heritage Lottery Fund and the Regional Growth Fund.  It is now a lively exhibition, conservation and events space with a varied collection of historic vessels including HSL 102, Landing Craft Foxtrot 8 and VIC 56.  Regular harbour trips are available on board a number of these craft from the Heritage Pontoon. 


Boathouse 4 outside


On the upper floor The Forgotten Craft exhibition tells the incredible story of small boats in the British Navy, including the display of several small craft.  The exhibition overlooks the main workshop, so visitors can watch real boatbuilding in action. 



The History of Boathouse 4


Boathouse 4 was originally constructed in 1938-40 and was the only boathouse to be built in a home dockyard during the rapid rearmament period of the 1930s.  Acknowledged to be an interesting example of industrial architecture in the International Modernist style, it stands in contrast to the Georgian and Victorian architecture around it.


The building was originally to be built in two phases, extending overall to Victory Gate.  It was intended for Phase 1 to be fully operational before Phase 2 commenced.  This required a temporary corrugated steel wall on the southern side.  However the Second World War broke out before Phase 1 was complete.  As a result, Phase 2 was never built and the temporary wall became permanent, still to be seen today.


In 1941-43 it is believed that the building was involved in the construction of the secret prototype three-man midget submarine X4 and later X-craft developments.  King George VI noted in his diaries that he secretly visited the Dockyard to view the X4 project. X-Craft were deployed to neutralise the German battleship Tirpitz in 1943. 


Boathouse 4 is the last boathouse built for the Royal Navy.  However, to this day the building continues to fulfil its intended role perfectly, something that its current occupants are enormously proud of.


CMB Replica Build


CMB4R under construction
CMB4R under construction



















In August 2023, the Boathouse 4 team completed the seven-year build of a brand new replica Coastal Motor Boat (CMB).  The boat is a fully operational reproduction of a 40ft CMB, and was built entirely by volunteers, guided by experienced boatbuilding professionals.  Although the build used modern glues, all the techniques are traditional ones that would have been deployed in 1916.  The boatbuilders worked from the original plans drawn on wax cloth and annotated by the designer John Thornycroft.  The new CMB, named CMB4R, conducted successful sea trials in September 2023.  


Nearly finished - May 2023
Nearly finished, May 2023
CMB4R undergoes sea trials, September 2023
CMB4R undergoes sea trials, September 2023





Boathouse 4 is always looking for enthusiastic volunteers to join their team!  Their volunteers get involved in:


- The conservation and restoration of small boats from the Portsmouth Naval Base’s collection that come to Boathouse 4 for repair or restoration.  Current projects include the restoration of the Armed Steam Cutter 26 built in 1910, and the building of a brand new Coastal Motor Boat 4 - Motor Torpedo Boat from scratch, both of which are projects funded by the Chancellor using LIBOR funds​.

- Leading a daily tour of their workshop floor telling visitors about the work underway   

- Research projects on the boats in their care, including creating interpretation for their visitors

- Telling their visitors about the significance and history of small boats in the Royal Navy and building boats in Boathouses 4,5,6,7

- Demonstrate aspects of woodworking/boatbuilding or ropemaking to visitors – training can be provided

- Welcoming and interacting with their visitors

- Help with their ‘hands-on’ activities and workshops for all ages

- Crew their fleet of WWII boats.


For an application form or more information please email: or call 023 9289 3328.


MGB 81 (c) Simon Jenkins
MGB 81 (c) Simon Jenkins




September 2023 The new Coastal Motor Boat replica, CMB4R, has been launched and completed successful sea trials. Full story



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