Can I lift the sunken TREASURE?! | The Science of Floating | Maddie Moate

Added: 2026-05-31

[00:00:00]Hi, I'm Maddie and I've been set an underwater challenge. There is a sunken treasure chest somewhere in this pool.

[00:00:09]And it's my mission to go and find it and bring it to the surface.

[00:00:13]But, I'm not allowed to carry it. So, if I can't lift it to the top with my hands, I'm going to have to use science to help me instead. But first, let's go on a treasure hunt.

[00:00:50]I found it. It's here.

[00:00:52]I love diving for things in the water, do you? But the rules say I can't lift it. So, I'm going to have to use science and one of the most important skills you can learn for when you're in the water, floating.

[00:01:06]So, what is floating and why is it so important for staying safe in the water and having lots of fun aquatic adventures?

[00:01:14]Why is it that some things float, like these pool noodles and this swim ball, but other things like the treasure chest sink? I think it's time for a game.

[00:01:27]Does it sink OR DOES IT FLOAT? LET'S FIND OUT WITH MADDIE Moat's [music] Okay, let's unlock the science of floating with these objects. All you have to do is guess, will it sink or will it float?

[00:01:43]A pool float.

[00:01:44]What do you reckon?

[00:01:47]Float or sink?

[00:01:51]Float, of course. That was an easy one.

[00:01:54]A plastic ping pong ball.

[00:01:58]Float or sink?

[00:02:02]It floats.

[00:02:05]A golf ball this time.

[00:02:09]Float or sink?

[00:02:13]Sink.

[00:02:15]Bye.

[00:02:19]What about a ball of modeling clay?

[00:02:22]Float or sink?

[00:02:25]Sink. [music] Straight to the bottom.

[00:02:30]Same stuff, modeling clay, just a different shape.

[00:02:34]Float or sink?

[00:02:38]It floats.

[00:02:41]What about me?

[00:02:44]Float or sink?

[00:02:48]Using the technique I learned from the Water Babies Swim Vincible Swim Team, I feel really confident floating in the water.

[00:02:55]I float and you can too, but more on that later.

[00:03:00]So, how did you do?

[00:03:03]Some interesting results there. The ping pong ball floated, but the golf ball sank, even though they're the same size and shape. Then the modeling ball of clay, that sank, but the modeling clay boat floated, even though they are made out of the same amount of material. So, what's going on?

[00:03:28]When people and things like Maddie Moat are in the water floating, they push down into the water.

[00:03:36]At the same time, the water pushes back, pushing us up.

[00:03:40]This pushing force is called buoyancy.

[00:03:44]>> [laughter] >> The more water a boat pushes out the way, the more water can push back. The more it pushes back, the more buoyant something is. And this is why even the largest, heaviest ships can float in the water.

[00:04:00]So, why doesn't the treasure chest float then? It's way smaller and lighter than the ship.

[00:04:07]Well, that's all to do with density.

[00:04:10]Things float on water if they have the same density or are less dense than the water they're in. Our problem is that the treasure chest is really dense, way more dense than water, so it has sunk to the bottom. But what does this actually mean?

[00:04:25]Everything in the world is made up of atoms, teeny tiny particles that we can't see. Even the water is made up of atoms. Take this little floating ping pong ball, which is full of air. If we zoomed in, we would see that the atoms inside are spaced out and very lightweight, a little bit like this.

[00:04:52]We say that it's not very dense. In fact, it is less dense than water, which is why it floats.

[00:05:01]Whereas if we zoomed in on this golf ball, we would see that the atoms inside are heavier and really packed in close together, a bit like this.

[00:05:13]We say that it is very dense. It is way more dense than water, which is why it sinks. If something has a higher density than water, like the golf ball, then it sinks. But if something has the same or a lower density than water, like the ping pong ball, it floats.

[00:05:35]Let's put some of this science into action. We already know that the treasure chest is denser than water, so it won't float. But I'm not allowed to carry it. So, to lift it to the top, we need something that is less dense than water. Something that is wide, flat, and buoyant. But what could we use? Oh.

[00:05:56]Yeah, a pool float could work. It's spongy and full of air and we know that air is less dense than water.

[00:06:03]The struggle is going to be getting something that floats to the bottom of the swimming pool.

[00:06:09]Wish me luck.

[00:06:20]Ready? Okay, three, two, >> [music] >> I think we did it. I think that counts, right? Three cheers to science to make it to the surface using a float, which is less dense than water.

[00:06:44]Which means there's only one thing left to do. We've got to open it up, right?

[00:06:53]Treasure.

[00:06:55]Yes.

[00:06:57]Do you remember what else can float? Me.

[00:06:59]And you can too, if you know how.

[00:07:03]Water Babies and their Swim Vincible Swim School is the perfect place to learn fun skills like floating. It helps you feel confident, stay safe, and feel strong in the water. Plus, if you ever fancied snorkeling or a spot of artistic swimming or even lifeguarding, being able to stay afloat is really important.

[00:07:20]Here's how the Swim Vincible team taught me how to do it. Gently lie back until your ears are in the water and you can hear the underwater world.

[00:07:28]The important thing is to relax and spread out your arms and legs like a starfish. Remember the modeling clay boat? The bigger surface area you create, the more surface the water has to push upwards on you. And this is how to make Maddie Moat float. If you're a grown-up watching and would [music] like to know more about Water Babies and their Swim Vincible program, then check out their website. I love how fun they make swimming and how they teach through play and discovery.

[00:07:58]I hope you had lots of fun with me in the pool today and are looking forward to aquatic adventures of your own. Swim strong, safe, and of course, stay curious. BYE.

[00:08:12]>> [laughter] >> OKAY, WE'RE GOING TO SIT CROSS-LEGGED.

[00:08:29]I'M IN.

[00:08:30]THERE SHE'S IN.