What are the disadvantages of Ming wheel?

Although the invention of Ming wheel is a great progress in shipbuilding technology, it still has serious defects. Generally, it is only applicable to ferries in inland seas and inland rivers, not to ocean-going ships. Because most of the paddles are exposed on the water, once the ship bumps badly, it will stir up very little water, so the thrust is very small, and even the wind and waves are too big to stir up water at all and will not be damaged, so the ship is at the mercy of the wind and waves.