Build a Boat (and a classroom culture)

Text: Build a Boat, Hope it Floats

The start of a new school year is fast approaching and as we begin to plan for our first days back with students I thought I’d share one of my favorite first day activities.

Editor's Note (August 2020) - See Kristin Gregory's post, . She has added a slide show for a remote learning version of the Build a Boat Challenge.

One of the most important components to a successful modeling classroom is the classroom culture. Modeling teachers need to build the kind of classroom environment where students respect the process of investigation and understand that the process of science learning is as important as arriving at correct answers. We want our students to see value in learning from each other and recognizing it’s okay to not have the best answer the first time you attempt something. In an attempt to instill these ideas from the first day of class I have my students build boats on day one.

That’s right, we build boats.

Here’s how the activity breaks down:

First, students are arranged in their whiteboarding groups, I usually try to put four students to a group, but three also works well. The students are given a challenge (figure 1).

Build a Boat Challenge Slide

Figure 1: The Build a Boat Challenge


They are instructed to build a boat using the materials I provide (figure 2). Each piece of material is associated with a cost. Aluminum foil? That’s $0.20 for every square centimeter. Duct tape? It will put you back $0.75 for every centimeter you take. Once they build their boats, they will float the boat in water and place pennies, one at a time, onto the boat until the boat sinks.

Build a Boat Materials & Costs list

Figure 2: Build a Boat Materials / Costs


The winner is the group who builds the boat with the best building cost to pennies floated ratio: total cost/number of pennies (figure 3).

Google Slide including Build a Boat - How to Win

Figure 3: How to Win


What do my students take away from this activity? First of all, they have to keep track of all the supply costs. They have to review how to use a ruler and what a square centimeter even is. They also have to present the data in a clear and easy-to-read way to rest of the class. As an added bonus, students start to notice that not all measurements are equal – some groups will report using whole numbers, some with one and some with two numbers after a decimal. Which is the best way? How can we be consistent and fair when taking measurements? What if one group reported their ratio as $3.9 for every penny and another group reported $3.92 for every penny? Who would win? What if someone reported $3.9245678 for every penny? Does that value even make sense? If ONLY WE HAD A SYSTEM OF MEASUREMENT THAT HELPED US DECIDE! Can you see where this discussion is headed? This is also the first time I introduce the idea of “for every statements”. This purposeful choice of wording helps my students conceptualize the mathematical relationships we report throughout the year. (Learn more about “for every” statements by reading Gary Abud Jr.’s ChemEd X article: .)

Finally, the kids have fun. They hypothesize, investigate, test, and troubleshoot on day one. They get to experience science. At the end of the activity I ask two questions.

“How many of you built the best boat you could have today?”

No one raises a hand.

“After watching your classmates, and observing the best parts of their designs, how many of you could build a better boat now?”

Everyone raises a hand.

This is the point.

We will learn from each other in this class, we won’t always get the best answer the first time, but that’s okay, we get to come back and improve on our work later. You know, like scientists.

This activity was adapted with the help of Ryan Bruick at Noblesville High School in Noblesville, IN. We built on an activity shared at a modeling workshop led by Dr. Levi Torrison.

You will find a Google Slide presentation with an outline of the activity and a list of materials with associated costs we have found to be useful here:



Also read Erica's post, .

See a follow up blog post, , written by Kristin Gregory pertaining to teacher collaboration through Twitter.

Join the conversation.

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Comments 8

Melanie Shedd's picture
Melanie Shedd | Mon, 08/04/2014 - 15:07

Does this take you 45 minutes?   How much class time do you devote to this?

Dan Meyers's picture
Dan Meyers | Tue, 08/05/2014 - 09:42

I'm always interested in fun projects and/or lesson plans to engage my kids. This seems like a great way to grab their interest and attention that first week. I think i will definitely utilize this for my honors chem 1 classes if the first week schedule pans out!

Erica Posthuma's picture
Erica Posthuma | Tue, 08/05/2014 - 15:34


I have done this in a 45 minute period, but I have also done this in a 90 minute block period.  You can alter the amount of time you give the students to plan and build to fit your needs.  If you need to split the activity, I've given them the first day to plan and build and then let them test on day two.   

Deanna Cullen's picture
Deanna Cullen | Wed, 09/03/2014 - 12:27

My colleague, a brand new teacher, and I tried this activity today. It was a huge hit! Students had a great time and they were eager to explain that the reason why they could build a better boat next time is because they learned from the experience. We ended up with boats that cost over $100, but the best boats were under $10. The power point was very nice to use. I printed off the sheet with the prices and left at each lab station since we don't have a projector in the lab area. We did this with general chemistry classes and chemistry essentials students. My colleague decided to allow for two 60 minute class periods for the chemistry essentials classes which tends to move at a slower pace. This will stay in my curriculum. Thanks for sharing it. 

Erica Posthuma's picture
Erica Posthuma | Sun, 09/07/2014 - 09:47

I am so happy to hear some of you tried this actiivty!  Please feel free to share your experiences with me - suggestions, student response, surprises - I would like to hear your feedback :)

Michele Richards's picture
Michele Richards | Fri, 07/31/2015 - 09:10

I found this activity through Twitter and tried it with my AP Chem students on the first day of school last year. I loved how easy it was to compare this task to what the students would experience throughout the year.  They would work cooperatively to solve problems all year. They would have problems that seemed familiar, yet they would struggle with how to arrive at the right answer. Many times there would be more than one way to arrive at a solution. I learned about the students' personalities by watching them interact. Some dove right in and were willing to try, fail, and try again. Others were so meticulous with planning that they ran out of time to build. Still others stood back and mostly observed, afraid to do something wrong or have an idea rejected. I will definitely use this again! Thanks for sharing! 

Lori Young's picture
Lori Young | Tue, 08/30/2016 - 10:23

I love this activity and plan on using it on Monday.  By any chance, can you please tell me if you just monitor the "supply station?" to prevent any inaccuracies in reporting the amount of supplies used by the teams?

Thank you!



Erica Posthuma's picture
Erica Posthuma | Tue, 08/30/2016 - 16:38

Hi Lori,

I don't monitor the supply station - mostly because if they do make mistakes reporting the amount of supplies it helps us have a good conversation about why keeping detailed notes is important.  At the end of the period I emphasize the point of the activity was not who "won" the boat design - but how we will learn from each other throughout the year.  

Although, we did have fun challenging classes across the country over Twitter!