Float or sink?

This morning my class was observing a creative boat that I will describe: It had two big water bottles then it was taped together then it had a balloon with a lollipop stick taped to the bottles then we had to fill it up with water. Then we observed and we saw that some of the creative boat had sunk but a little bit of it was floating Awatea said ¨because there´s still some air in it that causes the boat to still float and it doesn't sink to the bottom¨ when we finished observing Whaea Verbina said ¨ who said it would sink and who said it would float¨ Steven, Ebony, Quin, Ngapua, Kody, Honekai, Mahuta, Tuishaly, Kosena, Eva, Awatea, Delina, Tamarah and me said that it would sink but Xavier, Joshua and Manu said it would float poor them because it sunk I think they need more learning on this.