Using a snorkel properly will give you a clear vision of what's going on under the sea without having to breathe water.
Test your mask and snorkel together to determine fit and comfort.
Position the small rubber strap that attaches the snorkel to your mask so that the snorkel passes just above your left ear. (If you are using a special left-handed snorkel, it will be on your right.)
Take a deep breath, bite down on the mouthpiece and submerge your head in the water.
Exhale sharply once to clear any water that may be in the snorkel shaft. This is commonly called 'blasting' or 'purging.'
Inhale gently at first in case there is any residual water. Blast a second time if needed, and continue to do so whenever water enters the snorkel.
Learn to move gently on the surface'rapid or abrupt movements can fill the snorkel with water.
Inhale and hold your breath, then dive to explore the underwater environment around you.
Ascend, make sure the snorkel end is above the surface, then purge to clear the tube of water.
Breathe cautiously to be sure the snorkel has cleared completely. If you don't have enough air left to purge, lift your head above the surface and take the snorkel out to breathe.
Make sure you are gripping the mouthpiece of the snorkel securely with your teeth.
Exhale forcefully through your mouth. The majority of the water should be expelled from the tube. This method is commonly called "blasting" or "popping."
Inhale gently at first in case there is any residual water. Blast a second time if needed.
Continue blasting whenever water enters the snorkel.
When you're floating facedown in the water in a relaxed position, the snorkel should extend vertically above your head. It's normal for snorkels to flood with water periodically because of wave action as you move about on the surface. Practice purging your snorkel until it becomes routine. If you are ascending to the surface, you can tilt your head back and exhale a small puff of air into the snorkel. Then as you rise, the air puff will expand and clear the tube naturally so that by the time you reach the surface the snorkel is already clear. This trick takes some practice to perfect, but it requires less effort than blasting. Some snorkels have a type of one-way valve at the top that is intended to stop any water from washing inside while on the surface. These rarely work as advertised and are not needed.