The Essentials

The two absolute essentials for snorkeling are a snorkel and diving mask. A pair of fins is usually included in the list because of the immense value they add to the experience, though it is possible to snorkel without them.

Snorkel

A snorkel is a lightweight, curved tube, typically J-shaped or L-shaped, and made with rubber or plastic. It generally measures about 30 centimeters in length, and has an internal diameter (called a bore) between 1.5 and 2.5 centimeters. One end of the tube is fitted with a silicone rubber mouthpiece, and it is the act of breathing through this while submerged in water that makes snorkeling what it is. This means it is well worth your while to choose a snorkel with which you feel comfortable, and to understand all its features before you begin.

While some variation in dimensions is common, the tube of a snorkel should never exceed more than 40 centimeters as this would allow you to go to a depth at which the lungs cannot draw in air from above because of high water pressure. The inner diameter should be neither much wider than the norm, as this would result in increased respiratory dead space and repeated inhalation of previously exhaled air, nor should it be much narrower. While a narrower diameter would reduce the amount of exhaled air trapped in the tube, it would also make the process of breathing itself more strenuous.

A basic snorkel simply comprises of a tube and mouthpiece, and usually a clip to secure it to the diving mask. If you are interested in something a little more advanced or for greater comfort and convenience, there are several additional features you can look out for.

Snorkels may come equipped with an emergency whistle, an extremely useful safety feature especially if you are not intending to stick close to a group.

A device fitted in several mid-range snorkels is a splash guard or wave deflector, which is attached to the top of the tube and minimizes the amount of water that may enter from above the surface. A complementary feature is a sump at the curve of the tube, which allows water that does enter to collect in it without blocking the airway. Additionally, a non-return valve and purge chamber can assist in easily dispelling the collected water while breathing out. While exhaling forcefully even without these devices can replicate the same process, it would certainly require more effort.

The quality, adjustability and comfort of each of these features can vary with different snorkels. While a simple model may be sufficient if you are trying the activity for the first time or for a short duration, you may want to consider more advanced snorkel gear if you are more invested in the activity.

Source: https://www.jenreviews.com/snorkeling/