It is possible to get water inside your paddle. This can happen when there is a break in the seal on one of joints and water finds its way in or if a blade has been damaged/punctured. There are a number of solutions for “getting water out of my paddle” ranging from the simple to the extreme.
In most cases if water is a problem then it would have found its way into the paddle shaft. However some paddle blades have a hollow or foam core. If punctured a hole can be created that allows the blade to also take on water.