 The architect Anthony Salvin , an expert on adapting medieval buildings , was employed by the Squadron to remodel the building between 1856 and 1858 . He enlarged the house , altered its profile and built a new tower , platform and a gatehouse , along with a service wing , a ballroom and more accommodation for the members , at a cost of around £ 6 @,@ 000 . Prince Albert and Edward , the Prince of Wales , visited the castle before it was formally reopened in 1858 ; the work received mixed reviews , one local newspaper likening the result to " a discipline establishment " . Cowes became a major centre for yachting . After the destruction of William IV 's miniature frigate the Royal Adelaide in 1877 , its 21 brass cannons were donated to the castle by the Prince of Wales . 
