Assume you have a can (representing a boat) with a hole in the bottom floating in a tank filled with water. The "boat" will start to sink. Now to my question.. My teacher told me that the speed of which water is runnig through the hole of the can is constant. But i can't seem to understand that, since (i think) the speed depends on the pressure which constantly increases as the boat is sinking - wouldn't that mean the speed increases aswell!??