Welcome to brain Stuff from house stuff works dot com where smart happens. Hi. I'm Marshall Brain with today's question, what is a semi submarine? So we've all seen submarines, and almost always their military submarines, and there's a reason for that. Submarines tend to be quite expensive. There's two reasons why they're expensive. First, any sealed container full of human beings presents problems. You have to deal with the
oxygen supply. You have to deal with this carbon dioxide removal, and you have to worry about humidity from the error that we exhale from our lungs. So it takes a fairly precise system to keep the oxygen level at about You have to have chemical scrubbers that remove all the carbon dioxide, and you you need to do something with the humidity or you get all this condensation on the inside
walls of your submarine makes a mess. The second reason why submarines tend to be expensive is that when you stick that sealed container underwater in the form of a submarine,
the problems multiply. You have to deal with water pressure now, so the container, including its windows, has to be strong enough to handle depth and it doesn't take much depth to create a lot of water pressure, and then you also have to worry about how you're gonna dive and surface, So you have to have ballast tanks, and you have to be able to fill those tanks with water or
blow the water out of them. And you have to make your container completely leak free, obviously, and that's not a simple thing, especially if you're gonna put windows in it, and that's why a lot of military submarines don't have any windows at all. So what's the solution. What if you would like to create a submarine, but you'd like the lower the costs so that normal people can afford them, One thing you could do is you could eliminate the
sealed part of the container. Second, you could eliminate the problems with pressure by controlling how deep your submarine can go and keeping it really shallow. And third, you could eliminate the need for diving and surfacing, and therefore you can get rid of all the ballast tanks and blowing the tanks and everything that has to go with that. Almost all the problems go away if you start putting these constraints on your submarine. And that's the idea behind
a semi submarine. A semi submarine lets you, as a passenger, ride around underwater, but the depth is very limited. It might be six feet at most, and the submerged part of the submarine remains open to the air above, so you don't have to worry about pressurizing the container or keeping the leaks out like you do with a submarine that goes down a hundred feet. So here's one way to think about a semi submarine. Think about creating a
small room. Say the size of a closet. It might be, you know, four by four ft or four by six ft or six by six feet in size, and it might be six x or eight feet tall, just like a normal closet in your house might be. You make that closet out of a sealed container, either out of fiberglass or out of steel, and you put great big
windows in it so that you can see out. Those windows don't have to be exceedingly thick, because they're never gonna be much more than six or eight feet underwater, So you might make them an inch or an inch and a half thick if their glass maybe about the same if they're made out of acrylic. Now you put a couple of comfy chairs in this closet so you can sit and look out the windows. And now you just have to get this closet submerged in the water
so that it's underwater but won't sink. And the most common way to do that is to put some kind of pontoons on top of the closet that will keep the top of the closet up out of the water. That is the basic configuration for some semi submarines. And then you put a couple of electric motors on them, or a little um gasoline motor or something so that
you can move it around through the water. And if you're in a nice clear water, say around a coral reef, you can paddle around with this with this floating closet underwater, and you can see all kinds of stuff because the water is nice and clear. You can look and see the reef, you can see the fish swimming around the reef, and so on. Without ever getting wet, and without ever having to worry about scuba equipment or snorkels or anything
like that. You simply sit in your comfy chair, you look out the window, and you steer the boat around with some simple steering mechanism. Typically you find semi submarines in resort areas. So if you go to Hawaii, for example, you can find semi submarines that hold thirty or fifty people and you go down below and you're about six or seven feet underwater, sitting on a bench or a chair looking out great big glass windows that are an
inch and a half thick. Or you can go to resort areas and find little two persons semi submarines that you can tool around with on your own. Semi submarines were invented in the nineteen nineties and they've been pretty popular since their invention. They're popular anywhere where you would find things like glass bottomed boats. Be sure to check out our new video podcast, Stuff from the Future. Join how Stuffork's staff as we explore the most promising and
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