Scuba Snorkel
One of the simplest pieces of diving equipment is the scuba snorkel. Essentially, all snorkels are made of a length of tubing, to which is connected a mouthpiece on one end. A diver puts the mouthpiece end in his/her mouth, and the opposite end pokes through the surface of the water, allowing the diver to stay several inches under the water without having to come up for air.
The size of scuba snorkel barrel is an important aspect of their design. Wider barrels are typically used for divers with larger lung capacities. Those with less lung capacity are usually advised to use a thinner snorkel barrel.
In most cases, a scuba snorkel is made from either rubber or silicone. As a general rule, rubber snorkels tend to be less expensive but are more prone to becoming dry and cracked over time. Silicone snorkels have a much longer lifespan, on average.