Building a self-righting boat

Here I was building my boat. I used cardboard, an empty water bottle and sellotape to stick it all together. I drew the template on the cardboard and cut it all out. Then, after I stuck the empty bottle the top of the cardboard. Then the boat was complete.

We filled the bath with water, then I placed my boat in capsized. To my surprise, when we capsized the boat it automatically flipped right side up.

This shows that the upthrust of the water in the bath was more or equal to the weight of my boat so the boat flipped without me putting any plasticine on it.

weight

upthrust