Subdivision blurs the destroyer-cruiser boundary

Subdivision offers the best protection against sinking, yet small destroyers lack the volume to add it freely. More compartments restrict the spread of flooding, while each additional bulkhead and rearranged space has structural and machinery costs. Designers must determine whether engines and boilers can fit around longitudinal bulkheads without losing the horsepower per ton needed for destroyer speed. Those requirements push the ship toward cruiser-like size and internal structure, which makes the boundary between the two types increasingly porous.