This activity is one for which you can find a lot of different explanations on the internet, but most of them are wrong. Some say that the soap is ejected from the back of the boat. Others say that water is ejected from the back of the boat. Still others say that there is surface tension in front of the boat and none in back of the boat. The one that is most accepted by scientists is the surface tension explanation. That is the one that will be used here. This activity is inquiry because students have likely not done the activity before, you have not talked about unbalanced forces before, and students likely cannot guess what will happen before trying the experiment.