the shape of a bowl, and appears to have been emptied of air, due to the greatly increased air pressure inside of the tank. Sounds inside the tank at pressure sound as if they are "far away". During the controlled release of pressure from the tank, the air in the chamber becomes quite chilled and a fog forms in the chamber, often precipitating as a sort of dew. (See adiabatic expansion) Once pressure is fully released, the candidates are examined with an otoscope to check for ruptured eardrums. Candidates with ruptured eardrums are removed from the testing cycle until healed, depending on the severity of the injury. Escape training The third phase of testing for submarine fitness is escape training, utilizing the Steinke hood submarine escape appliance, or colloquially known as the Steinke hood or, more familiarly, as "Stinky hood". This is a very complex device, but essentially it covers the head and shoulders during ascent from a stranded submarine, allowing air to escape during ascent, which is necessary as the expanding air in the lungs would otherwise cause disastrous injury. Actual training with the Steinke Hood is done in a Submarine Escape Training Tower to simulate a submarine stranded on the floor of the sea bed. The escape testing proceeds as in the pressure test, except that this time, a hatch in the floor of the pressure chamber is opened. The chamber immediately adjoins a cylindrical tower full of water, tall enough to simulate the depth of a stranded submarine. Because the air pressure inside the chamber is equal to the pressure of the water in the tower, the water does not enter the chamber. Donning the Steinke hood, the testee enters the water and immediately commences a rapid ascent, due to the buoyancy of the escape device. As they ascend, each testee must allow the air in his lungs to escape, this is facilitated by yelling as loudly as possible. Typically they are told to yell "HO HO HO" repeatedly. If one does not forcefully and continuously expel air from the lungs in this manner, they may be gravely injured or killed. The air exiting the lungs is allowed to exit the hood through a set of two one-way valves, keeping the device inflated but not over-inflated. Upon reaching the top, the testee swims to the side, climbs up, removes his Steinke Hood, deflates it, stands at parade