The Strongest Boat challenge

We do this in a two – class session because of time restraints and I really like to have the full 2 hours to make and remake the boat for kids.

So in this lesson, we had been studying weights and measurements the class before and this was our next step. We wanted to make a boat that could hold as much weight as possible, so we filled up a tub with water and then I gave them the Challenge


  • Must use classroom materials
  • No “whole” bottles”
  • Cannot touch the boat after it’s been placed in the water
  • Add coins to the holding tank until the boat cannot support the weight and sinks
  • Coins may “ONLY” be placed in a holding tank
  • Gather up the coins used and weigh them on the scale
  • Unlimited number of revisions

They were allowed free reign of the materials available in class. I made plastic bottles available but I felt that having whole bottles was too easy so I cut them in halves and/or thirds.



  • chopsticks
  • popsicle sticks
  • duck tape and scotch tape
  • plastic bottles
  • paper cups (for the holding tanks)

The thing I loved about this project was that the students always wanted to figure out how to make their boats stronger, and so that’s what I focused on after each student’s boat sank…encouraging them to find new ways to sturdy the ship!


I highly recommend this project. There is so much you can teach from this lesson and it gives students a real chance to put their minds to work! Highly recommended.

-Pete at American Pacific