Your Own Underwater Robot?

Doug Levin is the Associate Director for the Center for
Environment and Society at Washington College in Chestertown, Maryland,
and is an expert in underwater exploration technology, as well as
designing fun programs that teach complex engineering concepts.

I briefly mentioned Aquabotz in my introductory post. The Aquabotz STEM (Science, Technology, Math and Engineering) program allows groups of students to work poolside to design, build, and launch a working underwater robot in a little more than an hour. I’ve done this with classes down to the 7th grade, and have never had a student group fail in this project in the 10 years I’ve been offering it.  So, how did I come up with this idea to have students build their own robots?

I’d been working in the ocean exploration field since the 80s and became enamored with the use of Remotely Operated Vehicles (ROVs) to explore underwater.  By definition, an ROV is connected to the surface by a cable that we call a “tether.” The early ROVs were prohibitively expensive for individuals, but I looked at them and thought, “How hard would it be to make one myself?”  So, armed with knowledge of electricity garnered from my life-long hobby of model train building, and with bathtub silicone sealant, PVC pipes, and cable ties, I set out to build a working underwater robot for $150.  

My big impediment was the electric motors. “Where do I find waterproof
motors?”  So I looked, and found that others were using small, electric
motors and sealing them in the wax that is used to seal a toilet to the
floor. This was cumbersome and required heat to complete. “There’s got
to be a better way.”

One day, I was working on the boat and the
bilge pump came on. This is the pump with a float switch that activates
when a boat takes on water.  This was my “Aha” moment.  When the bilge
pump breaks, you can replace its motor with a cartridge. These
cartridges are waterproof, electric motors that can be purchased for
under $10 each. There…I had my waterproof, reliable motors

From there, I built the frame around it with ½” PVC pipe, switches,
speaker wire, and other stuff. I was very fortunate to have propellers
donated to me by Thorgren Tool and Molding in Valparaiso, Indiana. In
short order, I had a working underwater robot that I now call Aquabotz. 
I’ve written up the manual and the shopping list for anyone to build
one on their own. If you like, I can sell you the kit or build the
controller for you.  It’s a great homebuilt project, especially if you
have a pool, or are friends with someone that has one. Because it’s
powered by batteries, there are no electrical hazards to running this
device in the water; you can even swim with it safely. So, are you ready
to design your own underwater robot?

The Aquabotz program has benefited greatly from my association with the
Marine Advanced Training Education Center, located out in Monterey,
California. I thank the Education Center for their support.
Plans and parts list available from

yo.jpgAn Aquabotz underwater robot built using pvc, bilge pump motors, speaker wire, and model train switches.


A student-built Aquabotz being operated in a pool.


A teacher and an inner-city education center leader building
an ROV at a recent workshop.

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