Snorkeling equipment: the snorkel

There's nothing simpler than a snorkel: a mouthpiece and a tube.
Get used to using a simple model, with no siphon or valves for "automatic" water evacuation.
Even if some systems are effective, learning how to expel water is important. It's like learning to drive: doing it with a manual gearbox won't prevent you from using an automatic afterwards.
Snorkels are often slightly curved, to better fit the shape of the head. The mouthpiece is more supple and pleasant to the mouth if it's made of silicone.
The flat part is placed between the lips and gums, while the two lugs are used to bite down with your teeth and hold the snorkel in your mouth. The whole snorkel should not cause you any discomfort or irritation, and should be rigid enough to prevent the elbow from bending, thus interrupting airflow.
The tube should be large enough to allow you to breathe in comfortably.
The end of the snorkel should be brightly coloured. When you're lying on the water, this is the part that is most visible to another swimmer or a boat.
Choosing a snorkel therefore comes down to finding a compromise between mouthpiece size, length and tube diameter. The snorkel is an extension of your respiratory system.

At the surface, a long tube will fill less easily with water, but will require a greater respiratory effort.
A large-diameter tube will facilitate ventilation, but make it more difficult to expel water.
The snorkel slips under the mask strap, or is held on the outside by a plastic loop or small rubber strap.

Emmanuelle Levasseur, Julien Collet