Speaker: Good evening. My talk this evening will cover three main themes. First, I'll outline a timeline of how deep sea exploration vessels developed. Secondly, I'll describe the most recent of these, the Deep Sea Challenger, and finally, I'll look at some of the benefits of this deep sea research.

OK. To start with, let's look at how underwater exploration vehicles have developed over the years. The first manned deep sea exploration vessel was invented in the 1920s. It was called a bathysphere, better known as a Diving Bell. It was basically a round metal structure with windows with just enough room for two men to sit in, and it was lowered into the ocean on a cable.

{[The first descent in the Diving Bell took place in 1930, and in 1934 it went down to a depth of nearly a thousand meters, which was impressive for the time. ][1]}

The problem with the Diving Bell was that it had no power of its own and there wasn't much room for the researchers to move around.

{[So the next development after the Diving Bell was the bathyscaphe, a small manned submarine, invented in the 1940s. ][2]}

The difference between the two was that the bathyscaphe had its own power source which allowed the scientists to investigate in the depths of the ocean more freely.

{[A bathyscaphe called The Trieste reached a record depth of ten thousand meters in 1960.][3]}

{[Since then a new record has been set by James Cameron, who descended to a depth of eleven thousand metres for the first time in 2012.][4]}

So let's move on now to look at the submarine that took James Cameron so far down into the ocean.

{[If you look at the drawing of the Challenger you can see the pilot's chamber at the very bottom of the submarine. ][5]}

It's a very small section where the pilot sits and controls the sub and all the equipment on it. Now let's have a look at how the submarine is powered.

{[Going up from the pilot's chamber, in the middle of the sub, on the right hand side of the drawing, you can see a whole section covered in batteries.][6]}

They provide the power source that takes the sub all the way to the bottom of the ocean and back up to the surface again. Next to that there's another important part of the sub ' Ummm ' You probably realize that there's no light at the bottom of the ocean, so the sub needs to take its own.

{[If you look at the back of the sub, in the middle, just next to the batteries, you can see the panel of lights. ][7]}

They provide the light for filming and taking samples from the sea bed.

{[And one more part of the sub, which is important for navigation and to stop it spinning out of control, is the large fin at the back. You can see it at the back of the sub, at the top of the drawing.][8]}

OK, to conclude my talk, I'm going to ask a couple of questions. First, what is the purpose of this deep sea exploration and second, is it worth the expense?

{[I think one of the justifications for spending so much money on this kind of research is that it allows scientists to understand more about the surface of the earth][9]}, for example how it was formed and how it behaves. This could have important consequences for predicting earthquakes and saving lives through early warning systems.

{[Another reason this type of research is considered valuable is that by exploring unknown parts of the ocean we increase our knowledge of the availability of minerals for industry.][10]}

And, obviously, this could lead to huge commercial advantages. So the answer is, yes. In the long run this kind of exploration can benefit both the ordinary population and industry.