Rolling in the Deep. The Titanic would have been a very different film if the ship had a Roll Tube. The device is a pretty inconspicuous looking contraption that holds multiple hydrophobic foam boards that expand and inflate on contact with water. Ideal for when many lives need to be saved. All you have to do is pull out the foam boards and throw them in the water. The moment they touch water, they puff up and become highly effective flotation devices.