Float or sink

Today we had to test out one of our class mates boat to see if it will sink or float the boat was Honekai. What happened? We filled up the bottles with water that he used to build his boat with and tested if it will float or sink. It sunk why because the water that is in the bottle is more dense than the water it disabled and that is what density means. The easy part was knowing if it was going to sink or not. we had a vote and I picked sink I was correct with many others. The hard part was  making sure the hole boat was sinking because It was floating just a little bit. Why because the there was a bite of air in the bottle and air will make something float. The thing I will do next time we do that is to make sure I have the rite answer. Here is his boat.