It's amazing what you can accomplish when your dad's garage is full of useful parts and pieces, and your whole family is certified as scuba divers.
BB reader SaltySamaritan, aka Jordan Needham, dropped us a line via Submitterator to show off the dome-shaped, oxygen-filled underwater fort—nicknamed The Bubble Room—that he and his family built at the bottom of a Nevada mountain lake.
Made from an air-filled vinyl bladder, held in place by an intricate system of cabling connected to an octagonal frame of metal pipe, this amazing hideaway had me at, "Blurple burblup." I had to know more. Luckily, Jordan was kind enough to answer a few questions about how his family built The Bubble Room, the rules they follow to keep it safe and their plans for selling a commercial version.
Maggie: Where did this idea come from?
Jordan: I was in the shower, one day about four years ago, and I was just thinking about how cool it would be to have an underwater "fort" I wasn't sure how to make it happen at the time, but that's when the brainstorming started. So I called my brother Logan and we started talking about ways to do it.
Our original version was just a net stretched tight and secured to four rocks—one at each corner—and then a piece of plastic pulled under the net and an air bubble released into it from a scuba tank. Because the air is displacing water, the upward force of the bubble is equivalent to the downward force of the same volume of water on shore. So a bubble 10 cubic feet in volume would be basically 74.8 "gallons" of air at 8.35 lbs per gallon, which means a 10 cu. ft. bubble has 624.58 pounds of upward force! Pretty substantial.
Needless to say, by the time the bubble under the net was about the size of an average ice chest it had stretched almost 20 feet up to the surface then the net broke.
Maggie: How did you make the working version?
Jordan: So, I started thinking about how to spread the load out around the perimeter of the net, and a better way to anchor it. That's where the idea for the "ring" came from. We no way to bend the super heavy pipe we had so I cut it and welded it back together into an octagon.
The ring is attached at three spots with stainless steel cable to three giant rocks, and we wrapped the cable around the bottom of the rocks and secured it back to itself with cable clamps. The ring is galvanized steel with 1/4 inch wall thickness. I also coated it inside and out with "sand" colored Rustoleum.
The ring, itself, is now a semi permanent fixture of the lake and has been down there for about three years now.
To make the rest, we draped a piece of netting over a small dome tent and threaded a piece of climbing webbing through the bottom of it. We then attached loops of parachute cord to the webbing that were long enough to wrap around the ring and hook to a little nub welded every six inches along the top of the ring.
The dome is vinyl from the local fabric store. We switched from plastic because the plastic was kind of "cloudy" and the vinyl is optically clear. When The Bubble Room is not in use we take the net and vinyl with us and it is just a metal ring sitting on the lake bed. It takes one person about 15 minutes to attach the net and vinyl and fill it with air.
All the materials except for the vinyl where free!
Maggie: Where is this thing set up?
Jordan:Well, I live in Reno NV, and let's just say it's in a local alpine lake. Even though it isn't hurting the lake at all and there are entire trains in the same lake, there are some pretty fanatical people "keeping the lake blue" and they probably would have a problem with my little addition.
When we set it up, it is usually an all-day event. We have had the bladder and net attached and it full of air for eight hour stretches before. But, like I said, when we leave we take the net and bladder with us and it's just a ring sitting on the sand. It would only be noticeable if you happened to snorkel right over the top of it.
Maggie: Do local conditions make a difference on its stability?
Jordan: When it's super windy you can feel the surge of the water, even 20 feet down. With every wave that goes over the top, a little temporary cloud forms in the bubble, which is pretty cool. You get the same effect when you squeeze a two liter soda bottle that has a couple inches of water in it.
Maggie: How do you make this work as a fort? You have to refill the air occasionally, correct?
Jordan: Ya, we use a standard scuba tank to fill it, and replenish the air once it gets thin. A standard 68 cu. in. scuba tank will fill it almost twice. There are obvious safety concern with being in a bubble 20 feet down and all the oxygen being used up, so we try and play it safe—buddy system at all times, and when the air starts to get even a little thin we empty most of it and fill 'er back up with fresh air. [You can watch a video of "used" air being forced out of the bubble and up to the surface. --M]
Also, the air in the bubble is 1.5 times more dense than the air on the surface, because of the additional pressure, so it is a must to exhale on the way out of the bubble to the surface. The one lung full of air you breathe in down there would expand to 1.5 lung fulls on the way up, and ruptured lungs would ruin anybody's day.
Jordan: One last thing, I hold a provisional patent on the idea and have adapted a version to be installed in a private pool, with a fresh air pump constantly feeding it with more air than the occupants could use. Some day I would like to try and make a little business out of it, and go around installing them in people's pools. You can't tell me Snoop Dog or a mob boss wouldn't want to have a little Bubble Room of their own!
Many thanks to Jordan and his family! Great work, guys. I am jealous of both your fort and your crystal-clear waters.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.