Why do divers use helium gas in diving?

Answer 1

Helium is actually only rarely used in Scuba tanks, and then only when blended with other gases (most commonl oxygen and nitrogen to make trimix). However, the main purpose of adding helium is to reduce the narcotic effects of other gases when you descend to greater depths.

Breathing normal air, divers begin to experience nitrogen narcosis (or the "rapture of the deep") at about 100 feet. Beyond about 130 feet it starts to become debilitating. Beyond about 170 feet, divers can be rendered completely insensible. But with helium mixes, divers have been able to dive safely as deep at 300 - 400 feet.

Answer 2

It is often mixed with other gasses to create a mixture that will extend divers endurance, in extreme diving & deep diving mainly though.

*At extreme depths the pressure is high enough that if you had nitrogen in the tank it would become saturated enough in your blood that you would develop nitrogen narcosis. Helium wont be absorbed across the alveoli and will not react with your body so it is used for extreme depth's.

Improvement

It has nothing to do with endurance. Also, helium is absorbed in the blood in the aveoli and is absorbed by the bodies tissues. Helium is used for deep diver (diving deeper than 100 to 130 feet in the US) since helium is not as narcotic as nitrogen and a diver will have a clearer mind.

Answer 3

Because when Scuba Divers go deep, the normal air goes poisonous.

Improved Answer

Helium is used since it has very low (almost non-existent) narcotic properties. The nitrogen in air is highly narcotic at depth and adding helium allows one to dive without the effects of narcosis (where one's mind is impaired).

Answer 4

Helium has many benefits as well as disadvantages. This answer could get very involved, but keeping it simple, the nitrogen in normal air is narcotic which affects the divers ability to properly think and function on deeper dives. Helium is far less narcotic, so it is added to the air on deeper dives so the diver can function and think clearly since the narcotic effect is overall removed. Helium used to just be used on decompression dives, but now it is being used for recreational dives too in combination with air and oxygen for a mix called tri-mix since it contains the 3 gases of oxygen, helium and nitrogen. Recreational divers are now getting the benefit of a less narcotic gas by adding helium to their scuba cylinder to do 100 foot dives.

One benefit of helium is it is less soluble than nitrogen which is a positive benefit for the body when breathing a gas. However it also enters the divers tissues faster than nitrogen - which is a drawback since a diver will build up more gas in the body faster. But it also leaves the body faster than nitrogen - which is a benefit for technical divers that must do decompression stops. This rapid off-gassing effect can be further increased when a diver switches from a dive gas containing helium to a different gas at a decompression stop that does not contain helium. By switching to a gas during decompression that does not contain helium, then the helium in the body encounters no resistance in leaving the body which allows it to off-gas even faster. But helium has another drawback ... it has bad thermal property and will cause you to lose body heat faster as you are exhaling your body heat. If diving in colder water, this needs to be accounted for so you have plenty of underwater insulation.

So to sum up, helium is less soluble (a benefit during any dive) and will leave the body faster during decompression, but it also has the drawback of entering your body faster and being another expense that must be paid for. Therefore divers will use helium on some dives and not on others depending on the type of dive being made.

Answer 5

Helium is a very low narcotic gas. By adding helium, there is less nitrogen percent in the cylinder and therefore the gas being breathed is less narcotic. This allows divers to dive deeper with very little narcosis.

Answer 6

it doesn't affect the tank