The Snorkel

A snorkel is a flexible tube, generally made from plastic or stiff rubber, which connects a snorkeler to the surface air. Snorkels are a diver's lifeline, allowing them to breathe while their face is in the water. The right snorkel should let you breathe easily and comfortably for extended periods of time, without making you short of breath or light-headed.

Snorkel designs vary based on bore diameter and length, and should be chosen based on a snorkeler’s needs and body type. Generally, the larger you are the larger the diameter of your snorkel should be, as it will allow more air to pass through.

If the bore is too wide, however, it may make it more difficult to clear water from the snorkel. Similarly, although longer snorkels allow a swimmer to breath air at a deeper level, they also make it more difficult to take in air and during long dives may cause buildup of stale air in the tube. Most snorkels measure between 12 and 18 inches, but choose one that feels comfortable for you.
snorkels

If the bore is too wide, however, it may make it more difficult to clear water from the snorkel. Similarly, although longer snorkels allow a swimmer to breath air at a deeper level, they also make it more difficult to take in air and during long dives may cause buildup of stale air in the tube. Most snorkels measure between 12 and 18 inches, but choose one that feels comfortable for you.

Next note the construction of the snorkel’s mouthpiece. Because every diver has a differently shaped mouth, you should choose a snorkel that fits comfortably on you. A snorkel mouthpiece is composed of two parts, a large oval lip flange, which fits just inside the diver’s lips, and the bitepiece, which is gripped between the diver’s teeth. The bitepiece should be held securely between the teeth but does not need to be bitten down hard upon. The real seal is provided by the lips covering the flange.

As with dive masks, snorkels can occasionally become filled with excess water, often from splashing waves on the surface. Drain valves are a feature offered on some snorkels designed to let a snorkeler expel the water more easily. Drain valves are one-way valves that let a diver expel water from their tube while continuing to breathe. Even without a drain valve on your snorkel, clearing excess water from the tube is a very easy process. Simply breathe out sharply to force the water out the top of the tube. Nevertheless, some manufacturers claim that snorkel drain valves can make the process easier and more efficient by providing an extra outlet for the water.

Some snorkels come with special tips designed to prevent water from entering in the top. The most common design is a simple ping-pong ball held in a tiny cage. Another design utilizes diagonal plates at the end of the tube, which allow air in and out and water to flow out, but which direct incoming water out through the sides of the tube. Most divers find that such devices are unnecessary and ineffective, but some appreciate not having to worry about inhaling water from an unexpected wave. Snorkel tips may also reduce airflow into the snorkel, making it harder to draw in breath and increasing the buildup of stale air in the tube.

Finally, many snorkels are being designed with additional features. Some snorkels and masks have a clip system in place to make it easier to attach and detach the snorkel from the mask. Other snorkels are designed to be collapsible or to fold in half for easier storage and transportation. These additional features are often not necessary for a simple snorkel dive, but may be useful for other reasons.

http://www.snorkeling.info