A Mini Sub Under the Sea-ish Water in a Bottle

Yes, I know. It is an extremely long title. I was trying to make it sort of sound like the Spongebob theme song. Didn't turn out exactly like it but it's ok. :) The mini sub is basically a little pen cap with clay-ish PLASTICINE. I hope I spelt that write. When I first heard that word, I thought we were going to be doing something related to surgery. Or something that involves all those hospitaly stuff. :) The word just gives me that surgical feeling. Making it was much harder than I thought. It never worked like it was supposed to! When you squeeze the bottle, the pen cap is supposed to sink. Then when you release it, it should float again. Mine never did that. It either keeps floating along or sink like a rock. The people in the video must have used MAGIC! That must be the answer! Now I just have to look online for the magic spell that makes the pen cap move! Good thinking, good thinking. I'm going to find myself a little treat for being so very "smart". I do have to get my sleep now. It's getting kind of late. One piece of info that may or may not brighten up your day. I stood by the sink for nearly an hour trying to make that bottle thing work. Please do not make fun of me. I was very determined. :)