If you like gadgets, and you like the ocean, then you must like ROVs – it’s just that simple. For the uninitiated, ROVs (Remote Operated Vehicles) are small unmanned submarines that are used for underwater operations deemed too deep, dangerous or difficult for human divers. They’re tethered to a support ship, from which a human operator controls them in real time, watching a live video feed from an onboard camera. It’s all incredibly appealing to those of us who are fascinated by the prospect of what secrets lurk beneath the surface of the ocean... or of the local pond. A few dedicated souls go so far as to trying to create their own homebuilt ROVs, many of them turning to what has become the bible on the subject, Build Your Own Underwater Robot and other Wet Projects. Gizmag had a chance to talk to the two authors of the book, and found out what inspired them to pursue such an unlikely project.
Build Your Own Underwater Robot was written by Vickie Jensen and Harry Bohm, both of whom now reside in Vancouver, British Columbia. The book was first published in 1997, and it has since sold over 18,000 copies worldwide. It provides instructions for building two ROVs – the fairly basic SeaPerch, and the more advanced SeaFox. Both submersibles can reportedly be built using materials available at hardware stores for under US$100 each, and have maximum working depths of 3 meters/10 feet (SeaPerch) and 10 meters/33 feet (SeaFox). Although Jensen estimates that about half of their sales are to adult hobbyists, the book is primarily intended for youths.
“If you look at how science is taught these days, for young kids in elementary school, it’s fascinating, because they’re picking up rocks and leaves and stuff,” said Jensen, herself a former English teacher and maritime trade publication writer. “But as kids get older and they move through school, science becomes a lot of rote memorization, and it’s not as exciting. We’ve had huge drop-offs in North America in kids being interested in the sciences, and so Harry’s idea was to come up with a fun, easy-to-build, but robust ROV.”
Bohm designed SeaPerch when he was working at Vancouver’s Simon Fraser University, in its Underwater Research Lab. He had already been building small AUVs (Autonomous Underwater Vehicles) using “hardware store technology,” so the reach to designing a similar ROV was not a long one. “I built a couple in the lab, and tried them out in the test tank, simplifying the design even more based on these tank trials,” he said. “I then had kids [including Jensen’s two sons] come into the lab to build them, to see what difficulties they had in putting them together. That was the acid test of the design. If kids could build it then it would go in the book.”
While the relatively lightweight SeaPerch is propelled through the water using propellers powered by small electric motors, the heftier SeaFox utilizes electric bilge pumps. Bohm got the idea when he remembered his stint as a tugboat deckhand, where his duties included cleaning out the boats’ bilges. “I wondered if a twenty dollar bilge pump could work as a thruster for an ROV instead of a $20,000 one,” he recalled. “I did some experiments in my home fish pond and at the marina dockside. I found the pumps would work at up to 30 feet (9 m) depth reliably. And so I bought six more and built with my eight year-old son the first bilge pump ROV, which I called BilgeROVer... We changed the name to SeaFox because Vickie thought BilgeROVer was a bit too grungy.”
The non-cutesy book went on to inspire the creation of the Sea Perch program, founded in 2003 by the Massachusetts Institute of Technology’s Sea Grant College Program. The initiative sells kits containing the instructions and materials for a SeaPerch ROV, which teachers can build and use with their students. Jensen licensed the design of the submersible to the group, which has so far distributed kits to over 200 schools across the United States. A second group offering its own SeaPerch program is also now in operation, and is very active.
Build Your Own Underwater Robot is now about to enter its 11th edition, but that milestone is perhaps overshadowed by Vickie and Harry’s latest achievement – a 770-page, 7-pound (3 kg) tome entitled Underwater Robotics: Science, Design & Fabrication, which they wrote with Dr. Steven W. Moore. The book is intended as a step up from their previous collaboration, and is part of the Marine Advanced Technology Education (MATE) Center’s U.S.-wide marine education program.
It’s all been more of an adventure than they probably ever imagined, as Jacques Cousteau- and Sea Hunt-obsessed youngsters.
“The amazing thing to me is that this crazy spiral-bound yellow book just became some sort of underwater cult thing,” said Jensen. “It just took my life in a different direction and continues to do so.”
Bohm isn’t surprised by the popularity of SeaPerch and SeaFox. “They are fun to build and even more fun to operate,” he said. “As an example of why they appeal, just look at the MATE Center's website and the International ROV Competition. The number of students and adults involved in that event is staggering to me, and there are no huge cash prizes – not even little ones – they do it for the joy of creating a robot that can get wet.”
Below is a video of a SeaFox exploring British Columbia’s Buntzen Lake, provided by ROV hobbyist Leonard Whistler.
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