The ‘ship in a box’ comprises 21 ISO containers similar to those used on cargo ships, stacked to create a three-storey superstructure crowned by a bridge.
Royal Navy and Royal Marines board-and-search teams will use the realistic mock-up ship to strengthen their skills, ranging from the fast roping out of helicopters to searching hidden compartments and using artificial ammunition to neutralise foes.
The £1m facility features secret compartments and hiding places used by smugglers, drug runners and terrorists in the real world. It is scheduled to be launched in spring.
Currently, sailors and marines are using the Cossack building for compliant boarding training prior to moving on to practising with merchant vessels off Plymouth.
Royal Marines lieutenant Chris Carter said that the marines will still use Cossack, which mirrors part of a ship, for training.
"But this new facility will really test them as a team in an environment that’s as real as we can make it," Carter added.
"With the ‘ship in a box’ you actually have a proper merchant ship with every type of compartment you’d expect to find for real."
Construction of the site is underway near Trevol Jetty at the south-eastern tip of Raleigh and is scheduled to be completed in March 2014.
Image: Workmen at HMS Raleigh fitting out the compartments. Photo: Royal Navy.