Skip to content

Are you interested in floating and sinking, oceanography and/or beach science? This week we found a fascinating book at the library about a scientist who studies ocean currents by looking at trash that comes up on the beach. Let's find out more about his research and then perform some experiments based on his findings.

Tracking Trash: Flotsam, Jetsam, and the Science of Ocean Motion (Scientists in the Field Series) by Loree Griffin Burns is about Dr. Curt Ebbesmeyer, an oceanographer who studies the huge streams of water flowing through the ocean, called currents. In 1990 his mother pointed out an article in the newspaper about piles of sneakers washing up on the shores near Seattle, Washington. Dr. Ebbesmeyer turned his scientific curiosity to the problem, and discovered the shoes came from containers that had fallen off a ship during a storm months before. The sneakers floated in the ocean currents and ended up washing up on shore. By tracking how fast and how far the sneakers moved, he and other scientists could map the direction and speed of the ocean currents carrying the sneakers.

Activities:

(Note: always watch children around water).

1. Bathtub or pool currents

Try to create a current in a bathtub or pool using a hose or a handheld shower head. Partially fill the pool or tub with water, then create a fast current by shooting water through it. Try adding a plastic floating toy to track the movement of the water flow.

2. Floating high versus low

Dr. Ebbesmeyer also studied the movement of some floating bathtub toys that had fallen off another boat. He found that the bathtub toys moved to shore more quickly than the movement of currents would have predicted. Then he floated a sneaker and a bathtub toy in seawater. What he saw suggested the answer.

Do you have an old sneaker or similar object that you could use to test this question? Float an old sneaker and a plastic bathtub toy in a tub or pool. Do they look the same in the water? Do they move through the water the same when pushed by currents?

Dr. Ebbesmeyer used seawater for his experiment. How do you think that might change the results?

His idea was that the bathtub toys floated high up out of the water and thus caught the winds. When the wind helps move an object along, it is called the object's "windage."

It turns out the plastic tub toys had been packaged in sets of four, yet none of the packages were washed up on shore. He wondered how the packages might influence the movement of the toys, so he placed packages of toys in tubs filled with seawater. He found the packages fell apart overnight, and so the toys were moving freely very quickly.

What else might change how an object moves in the water?

3. Plastic brick floating

In February of 1997 a ship lost containers filled with over four million LEGO pieces into the Atlantic Ocean.

Gather:

  • Plastic bricks
  • container for holding water, sink or bathtub

Now you are ready to answer some questions.

Do plastic bricks float?
Can you build a boat out of them?
Do you think they would float differently in seawater?

Check out the Techbrick Site for some photos of a LEGO boat race to give you ideas.

Tracking Trash: Flotsam, Jetsam, and the Science of Ocean Motion (Scientists in the Field Series) by Loree Griffin Burns

I admit, I wanted to be an oceanographer when I was in fourth grade. Now through this awesome book I can catch a glimpse of the world of oceanography.

For your information, the last two chapters are more about the trash found in the oceans, the giant pool of trash that is circulating in the Pacific Ocean, and how damaging adrift fishing nets can be. The information would be a tie-in to a study unit on environmental issues, as well.

To continue the theme of beach science from the last few weeks, today let's investigate something else found at the beach.

boat

Boats!

Children are fascinated by boats and floating. You can do a lot of interesting science projects with boats, starting with some basic questions: How can huge pieces of heavy metal float? How are boats propelled? Can you really make a boat out of paper?

We already have covered some floating and boat topics in previous posts.

Why Things Float contains some experiments on floating and sinking.

The How long can a paper boat float? challenge, with the early results for paper boats challenge.
The yellow legal pad boats lasted five days.

boat

The Bathtub Buoyancy Challenge asked kids to find ways to propel boats across a bathtub without using their hands or electrical motors. The Bathtub Buoyancy results show several ways to propel toy boats.

It is always fun to build bathtub-sized boats. This video shows two handmade boats powered by battery packs and small electric motors that my son invented recently. A modified toy car powers the paddle boat; the air boat fan is a modified toy airplane propeller.

Why don't you try inventing a boat?

For more ideas, try

A Simple Steam Boat at Curious Cat

Miniature Boats at HowStuffWorks

Hope you have fun and let us know what kind of boat you invent!

Edit: To check the rest of the posts on beach science, follow these links:

Sea Horses and Other Fish

Shore Birds

Tide Pool Invertebrates

Beach Science Algae

Beach Science-Sand

Beach Science-Seawater

Are you ready for the results of the floating experiment for paper boats? (See "How Long Can a Paper Boat Float?" post)

A friend did this test, although she didn’t say what kind of boats or for how long. Our friend found “the one that lasted the longest was made from a wax paper sandwich bag.” Thanks M!

We folded 5 different boats out of various papers and then floated them in plastic bins filled with water. We left the boats in the bins outside for 24 hours.

paper boats

Here are our results:

1. We made a newspaper boat, inspired by the “Curious George” book. How did it do?

paper boats

The newspaper boat was getting soggy after about ten minutes and went down in half an hour.

2. Paper boat number two was a piece of computer/laser printer paper rescued from the trash.

paper boats

How did it do?

paper boats

It actually sunk right before the newspaper boat, although in the past I have had computer paper boats make it over night. Perhaps it was folded more tightly than this one or the paper was a different brand.

3. Number three was a small piece of bubble gum wrapper.

paper boats

It floated 24 hours. Go, gum wrapper, go.

4. The fourth paper boat was a folded piece of yellow legal paper.

paper boats

It was still going strong after 24 hours, although its bottom was a bit soggy.

5. Paper boat number five was also made of yellow legal paper, but it had a fancy wing design.

paper boats

It was also floating after 24 hours.

We didn’t try any coatings or finishes, which would probably have allowed our boats to float even longer.

Edit: See our final results

If you want to be inspired to make a paper boat, try reading:

Curious George Rides a Bike
by H.A. and Margret Rey
In this book, Curious George makes a paper boat regatta. The instructions for folding the boats are included.

The Complete Adventures of Curious George: 70th Anniversary Edition
by Margret and H. A. Rey

The Amazing Book of Paper Boats: 18 Boats to Fold and Float by Jerry Roberts, Melcher Media, Willy Bullock, Melcher Media

For more advanced boat builders (although you wouldn’t want to float them when you are finished). Assembly trick: investigate some of the tape adhesives used for scrapbooking.

Disclosure: The books above were from our local library. Also, I am an affiliate for Amazon. If you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.