I know the texture of the wheels on a roller ship (or the hull on a traditional ship) determines its drag coefficient. Are there materials that let us change t

I know the texture of the wheels on a roller ship (or the hull on a traditional ship) determines its drag coefficient. Are there materials that let us change that on the fly? For example, can we apply a magnet to the back of some material to change its surface to increase or decrease its coefficient of drag?