To act out the story of Jesus walking on the water, we made a cardboard boat. It was made from two gaylord boxes, which my husband got from work. One end of each box was cut open so that the flap could be taped to the inner wall of the other box, making them more stable. We also cut a door in the side so that the kids could get in and out easily. A couple of blue plastic tablecloths made the water around the boat.
If you know someone who has access to large cardboard boxes at their place of employment, consider yourself blessed! You can do so much with these!