no. oxygen and pressure is a lethal combination... 400ft has just to much pressure..
you will need nitrous to dive that deep... which is very dangerous.
Addition
Yes, technical divers can dive to 400 feet. But they do not breathe pure oxygen (or nitrous on the bottom). They breath a combination of helium, oxygen and nitrogen known as trimix.
Scuba tanks are typically filled with compressed air, which is a mixture of oxygen and nitrogen. However, some scuba tanks may also contain a noble gas such as helium as part of a special gas mix called trimix, which is used for deep dives to reduce the risk of nitrogen narcosis.
The altitude above which recreational dive planners should not be used without special procedures is 300 meters (1000 feet). At higher altitudes, the partial pressure of oxygen changes, affecting the dive tables' accuracy, so adjustments must be made to ensure safe diving practices.
Steel has been used as a tank material since the begining of scuba diving. Extremely durable and useful as a tank material but steel rusts. Buy a steel tank, assume that over the life of the tank it will cost you for a few tank tumbles to remove interior rust. Pay more for a steel tank than an aluminum one. Steel will last (almost) forever if you take care of it. There are steel tanks still in service today that were originally manufactured in the 50s. Aluminium tanks came out in the 70s. It's a softer material, the walls of aluminum tanks are thicker, making them a little larger than steel tanks of the same capacity. The big advantage of aluminum is that it doesn't rust and it's less-expensive than steel. You can find aluminum tanks cheap, for $100-150.
The Dive Quest saltwater aquarium contains 5.7 million gallons.
The average aluminum SCUBA cylinder holds 80 cubic feet of air at pressure. That means you are taking the equivalent of a closet's worth of air and smashing it into a cylinder much smaller than that. When full, the cylinder is at 3,000 pounds per square inch of pressure.When the valve is opened, it sends air into the (assumed) first stage regulator which is connected by hoses to gear such as two second stage regulators, instruments and your vest.So the SCUBA tanks don't so much USE the air so much as STORE the air at high pressures.
It depends on the percentage of the mixture You can adjust the percentage depending on desired depth and length of dive.
A dive shop sells all the required components for one to go underwater diving. They sell wetsuits, oxygen tanks, masks, fins, snorkels and accessories.
A dive that requires two tanks of air to complete
Submarines change their depth by use of ballast tanks. To dive, they open their tanks so that they become filled with water. They also angle their dive planes. To surface, they pump the water out of their tanks and fill them with pressurised air.
to keep the sub level or help it to dive and surface
Submarines dive by opening vent valves that allow sea water to push air out of their ballast tanks.
No.
The world record for a scuba dive (without protective gear, beyond a wet suit and oxygen tanks) is approximately 1029 feet. The immense pressure which builds exponentially as an object descends is sufficient to crush humans at a lesser depth, in many instances.
Yes - Junkers dive-bombers and massed tanks.
The standard 80 weighs about 32 pounds empty.
If you mean Scuba tanks, call a dive shop, if you mean emergency breathing tanks, call your local Fire Co.
Scuba tanks are typically filled with compressed air, which is a mixture of oxygen and nitrogen. However, some scuba tanks may also contain a noble gas such as helium as part of a special gas mix called trimix, which is used for deep dives to reduce the risk of nitrogen narcosis.