Underwater Fort

This is a clip of the short journey from the shore to a oxygen-filled underwater fort, named the bubble room. SaltySamaritan and his family has built it at the bottom of a Nevada mountain lake.
"The Bubble Room is an amazing, clear, underwater dome about 15 feet below the surface of an alpine lake. My brother and I designed and built the Bubble Room. When in the Bubble Room you stand in the sand 20 feet under water, looking out through the clear dome into the lake above you"
Where did this idea come from?
Jordan(brother and co-creator of the bubble room): 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. via