This toy is similar in design to the rubber band powered airplane, except it is a bath toy. It will be approximately 3-4 inches long. The hull of the boat is constructed of a clear plastic, so children can see the rubber band inside as they wind up the propeller. Children ages 4 and up can use this toy. While the propeller is securely attached to the axle, it could become dislodged with prolonged use and abuse, so a choking hazard exists for children under the age of 3.
Children can see how the propeller turns as the rubber band unwinds, propelling the boat forward in the water. They will gain a basic knowledge about boats, and how they float. They will also learn about how rubber bands can store energy, and how boats (and ships) move through the water.
The boat will be constructed out of a clear plastic. It would probably be easiest to construct if each half (top and bottom) was formed in a mold, and then snapped together. The top half of the boat can be a color like blue to appeal to children. The top and bottom halves will have to fit closely together, so no water can get into the boat. A non toxic silicone could be used in between the two halves to prevent any water from leaking in. If any water does get into the boat, or the rubber band breaks, the child's parent can unsnap the two halves, replace the rubber band, and drain the water out. This toy will cost under $10, based on looking at similar bath toys.