Category
page 1Underwater diving equipment
helium
Helium (from ) is a chemical element; it has symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements, and it does not have a melting point at standard pressures. It is the second-lightest and second-most abundant element in the observable universe, after hydrogen. It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and
snorkel
device used for breathing air from above when the wearer's head is face downwards in water
liquid breathing
form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid (such as a perfluorocarbon), rather than breathing air
diving equipment
equipment used by underwater divers to make diving activities possible
umbilical cable
diving equipment
dive light
light used underwater by a diver