Inspired by this video, the Magical Minds and I used cups, bowls, plates and hot-glue to build water-powered boats.
Later, we discussed as a class why the boats behaved this way. We came up with a few theories: the fountain's spray was disrupting their movement, the straw was too small (or too large), the material was too light, the shape of the boat changes how the boat moves...
Here's a fun home connection
Try one (or many) of these variations on our experiment: float the boat in a calm body of water (eg. bathtub), build a new boat with different materials, build a different shaped boat, or try using a different shaped straw.