If you can play with dolphins on the water surface, you can lean underwater techniques and dive into the water to play with dolphins.

■Valsalva maneuver

When you start to descend and get pressure, you will feel something wrong with your eardrum.
If you feel uncomfortable, use the valsalva maneuver.
The Valsalva maneuver is performed by forcibly exhaling at the same time you are pinching your nose while keeping your lips tightly closed.
If you feel that the inside of the eardrum is pushed, it is OK.

Practice wearing a mask and snorkel on land.
If you can not success the valsalva maneuver by breathing out from your mouth , you can put the back of your tongue behind your upper teeth to prevent breathing out.

The trick to the valsalva maneuver is to do it early and often.
If you can not success the valsalva maneuver, please ascent a little slowly and try again. In addition, your easy valsalva maneuver is that your ear about which you can not success the valsalva maneuver should be located upper side than other one.

If you feel pain in your ears, stop descent.

■Mask blow

Put air into the mask from the nose.

If you feel the mask sticking strongly to your face while diving, perform a mask blow.

Mask blow eliminates discomfort.

■Mask clear

This is a method for clearing any water that might accidentally get into your mask while diving.

While pushing with your hand on the upper part of the mask’s frame, slowly blow air from your nostrils while gradually looking upwards towards the water’s surface.

It is easy to clean any water from your mask.

■Dangerous breathing method

A breathing technique for snorkeling in which you quickly and deeply breath a few times to lower the concentration of carbon dioxide in your body.

Hyperventilation allows you to breath hold for a longer than usual period of time.

However, when done to excess, the lowered concentration of carbon dioxide fails to stimulate the breath response in the respiratory centre, causing a loss of consciousness due to lack of oxygen.

Often occurring on or near the water’s surface, the term “Shallow Water Blackout” is used.
As a loss of consciousness in water is clearly dangerous, never hyperventilate to excess.

Also, it is forbidden to receive air from scuba divers while diving because of the risk of lung rupture.

■How to play with dolphins

Guess the dolphin swim line and relax and dive head first.

Wait for the dolphins to come underwater.

When the dolphins come, srotate sideways according to the movement of the dolphin on the water surface while looking at the dolphins eye.
Turn your stomach outwards and rotate your body.
The dolphins will be interested in you and rotate together.

If you get used to diving, try the underwater vertical rotation.
Turning the body while looking at the position of the water surface and the water bottom, you can rotate well in a well-balanced manner.

If no one is underwater, the dolphins will go somewhere.
If someone always stay underwater in order, you can play with dolphins longer.

Underwater vertical rotation