Scuba diving skills - Equalizing your ears

As you descend, pressure increases on the dead air spaces in your body, especially the ears and sinuses. It also increases in the dead air space in your mask. This is because the air is being compressed. To equalize the air space, you need to add more air to these areas.

The sign that you need to equalize your ears is unmistakable. There will be a feeling of building pressure, and if you don't equalize, pressure can very quickly turn to pain. The solution is a technique called the Valsalva maneuver.

To equalize, pinch your nose shut and gently try to exhale through it. The air you're trying to exhale will be blocked by your pinched nose, so it will end up in the dead air space in your ears, which equalizes the pressure. Swallowing also helps.

Some people find that wiggling the jaw while swallowing is effective in stubborn cases. You can even try all three techniques at once—a variation on rubbing your stomach while patting your head. Most divers continually equalize their ears as pressure changes during a dive. Sooner or later, it becomes second nature.

If you can't equalize, don't force it. Signal to your buddy and the dive master that you have a problem with your ears, rise up a couple of feet (until the pressure lessens), wait a few moments, then try again. Most people can equalize if they take it slowly enough.

If you're on a group dive, the group may continue to descend at the normal pace. (This contingency should be covered in the dive briefing.) You and your buddy can keep track of the group by swimming above them or following the reference line, if there is one. Then you can descend at your own pace. If you can't equalize your ears, you'll have to abort the dive.

To equalize the air space in your mask, simply blow out through your nose.

Troubleshooting:

Don't wait until your ears hurt. Start equalizing the moment you begin your descent. This prevents the painful buildup of pressure and keeps little problems from turning into big ones.

Do not force it! Several slow, gentle attempts are better than one forced attempt, which can damage your ears.

Never go deeper if you continue to experience pain. Stop or rise a little. Wait until the pain stops, then try again.

If you cannot equalize you have to end the dive.

Source: gorp.away.com