Why do deep-sea divers have to wear a strong diving suit?

Answer 1

Deep sea divers wear diving suits in order to prevent their body by the harmful effects of maximum pressure at greater depth in seas and ocean.

Answer 2

for protection, as astronauts need to wear space suits to do space walks. Humans are fragile beings. Our skeletons and bone structure can only work in a narrow range of pressure around the atmospheric pressure [~1x105 Pa at sea level] -- we have adapted to earth's atmosphere. In deep seas, the human body will encounter a pressure [Pa], in addition to atmospheric pressure, equals to rho*g*h, where rho = water density [~ 1000 kg/m3]; g = 9.8 [m/s2]; and h is the water depth [m].

At h = 1 [km], P = 1000 * 9.8 * 1000 ~ 1x107 [Pa], which is 100 times the atmospheric pressure! The diver will experience a crushing force, implode, and die without protection (see the special effects of the movie "the abyss."). As opposed to the outer space, the astronaut will explode and die without protection (see the special effects near the end of the movie "total recall.")

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Answer 3

Deep inside the sea, there is much more pressure and as such much more quantity of nitrogen is dissolved in body fluids and fat.When deep sea divers comes out suddenly on the surface of water, this dissolved nitrogen comes out forming air bubbles in the body cells and blood vessels causing serious damage. So deep sea divers have to were very strong suits.

Answer 4

To keep the immense pressure from crushing them.

Addition

Unless in a 1 atmosphere suit, it will not protect from pressure and a diver will never be crushed anyway. So the answer is for protection and warmth.