Deep-Six Underwater Systems, Inc.
"Add Depth to Your Life"
Contents

Table of Contents

Introduction
1 Pressure and Gases
2 The Face Mask
3 The Snorkel
4 The Fins
5 Weight Systems
6 The Knife
7 The Wetsuit
8 Pressure and Water
9 The Ear and Pressure
10 The Sinus and Pressure
11 The Stomach/Intestine and Pressure
12 The Lung and Pressure
13 Barotrauma caused by External Air Spaces
14 The Buoyancy Compesation Device (BCD)
15 The Scuba Cylinder
16 The Scuba Cylinder Valve
17 The Regulator
18 Density and the Diver
19 The 4 Gas Laws
20 Hand Signals
21 Carbon Monoxide Poisoning
22 Hyperventilation
23 Nitrogen Narcosis
24 Diver's Flags
25 Sound Underwater
26 Color Underwater
27 Decompression Sickness
28 Breathing Oxygen
29 Deep Diving
30 Thermoclines
31 Thunderstorms
32 Underwater Life
33 Open Water Dives
34 The Final Examination
35 The Environment
36 Advanced Course



3 - The Snorkel

     Snorkels are to skin diving as the scuba is to scuba diving. To be able to swim with fins for long distances, while keeping the head looking down, and not having to turn and breathe makes all the difference in the world.

     However, snorkels in scuba diving are becoming less popular. Even though most certifying agencies still require the use of the snorkel, the fact of the matter is they are rarely needed, cumbersome, and annoying. The main purpose for using a snorkel during a scuba dive, as is stated in the textbooks, is to allow the diver to swim on the surface for long distances without the need for trying to breathe by lifting the head out of the water. Get over on your back, enjoy the swim, and talk to your buddy while you are doing it!

     Some of the things to look for when purchasing a snorkel are:

  1. Make sure the bore of the snorkel is the right size. If the thumb fits snugly in the top of the snorkel it is correct. A snorkel bore that is too small will not allow enough air to flow through and will make breathing hard. One that is too large will make it difficult to expel the water after surfacing.
  2. Some snorkels have a flexible section near the mouthpiece. The section is corrugated so if it is bent it will not close. The reason for the flex is to allow the snorkel to hang straight when not in use. In that way it does not interfere with the scuba regulator. Be sure the interior of the corrugated section is smooth. The corrigations should not continue on the inside because water will trickle down the grooves and into the diver's mouth.
  3. The snorkel may have a purge valve. This is usually a one-way flap at the bottom. Its purpose is to let the water fall through this valve when the diver surfaces. The water in the snorkel will fall to the level of the ocean's surface. The remainder of the water should be blown out by the diver forcefully exhaling. Some will go out the top and some will go out the purge valve. Unfortunately, purge valves will leak if they get the slightest sand under them. If a leak occurs the diver has to bend the purge valve flap back and rinse all the sand from the area. Purge valves add to the price of the snorkel.
  4. Check to see how the snorkel is removed from the mask. Some snorkel keepers are in the shape of a figure eight. Sliding them up and down a dry snorkel is difficult. When using that type of keeper most divers simply leave the snorkel attached to the mask. However, if you have purchased a mask box to store the mask in, it will be impossible to close it with a snorkel attached. If that be the case purchase a snorkel with an easy mechanism for removing and replacing it on the strap of the mask.
  5. The mouthpiece should be comfortable in the mouth. After all, you may be biting on this for several hours at a time. As gross as it may seem, stick the thing in your mouth prior to the purchase. The dive shop should have an antiseptic spray, or at least a sink with soap and water to avoid germs.
  6. Silicone is the way to go. Forget the black rubber varieties. They rot from oil and the sun. They do not show contamination. See the comments below about the minor problems with silicone.
  7. You do not need any device to keep the water from entering the snorkel when going under water. Learn to blow the water from the snorkel as experienced divers do. It will save you money and increase your air flow!

     Snorkels are traditionally worn on the left side of the diver's mask. That is because the scuba regulator comes over the right shoulder and both would conflict with each other.

     The snorkel should be attached to the outside of the mask strap rather than putting it under it. Masks may leak if the snorkel is between the strap and the head,  and if a keeper is not use the snorkel may be lost without warning. Also, it may become uncomfortable after a period of time to have it pressed against the head.

     Proper breathing is important for pleasurable skin diving. The breathing should be longer and deeper (not faster) than usual. It is important to blow as much air out of the lungs as is comfortable. Short breaths would simply fill the snorkel with waste air that would be inhaled over and over again. A real shallow breath would not bring in any fresh air and the diver would suffer from oxygen starvation. Long, slow breaths are the key to enjoyable skin dives. The exhale should be fast followed by a deep inhale. Then hold your breath for a short time. Your expanded lungs will help to maintain buoyancy!

     Lastly, there are two methods of getting water out of a non-purge valve snorkel. One is to surface and blow as hard as possible through the mouth. This burst of air should eliminate most, if not all, the water from the snorkel. Be careful on the inhalation. Start slowly just in case there is still a little water remaining. If so, there will be a sprinkling of water drops into the mouth. A quick inhale could cause coughing. If water remains in the snorkel, breathe in slowly until the lungs have sufficient air to blow out hard again. The second method of clearing has to be done in water where the diver can rise to the surface in a vertical position. On the way up, the head is tilted back so the diver is looking directly at the surface. As the surface is neared, air is gently blown into the snorkel continuously. As soon as the surface is reached, the head is brought to the position where the diver is looking toward the bottom. The snorkel should be completely empty! The effort is so slight compared to the forceful exhalation technique, skin diving can be done for hours without chest discomfort!




Copyright Information about this text, DIVING WITH DEEP-SIX is as follows: Copyright 1996 - 2007 by George D. Campbell, III; President. All Rights Reserved. This file may be posted on Electronic Bulletin Boards for download, but may not be modified, printed for distribution, or used for any commercial purpose without the author's written permission.
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