 She was built with a transom, or flat, stern, to improve cruising efficiency, but the dead water caused by such a form meant that mines tended to be sucked back into the hull when they were launched; an obviously dangerous situation for a minelayer.As a result, she was rebuilt with a traditional cruiser, or rounded, stern, increasing the length by .As built, "Adventure" was long overall and between perpendiculars, with a beam of and a draught of at deep load.