All divers are familiar with equalising and there are several techniques to get it done, depending on the type of dive you’re doing. The need to equalise when diving is quite straightforward. As you go deeper underwater, water pressure increases on the outside of your eardrum, which requires you to increase the pressure from the inside. This is done by letting more air into the inner ear (Boyle’s law) via the Eustachian tube which connects to your nose and throat; equalising. If one does not increase the air pressure behind the eardrum, the water pressure at increasing depth would exert increasing pressure on the eardrum, which would lead to stretching and rupturing. A study has shown that when reaching 10-15 meters underwater without equalising, the eardrum is likely to rupture.
We had World Champion freediver Vitomir Maričić dive up to 100 metres with SurfEars and he had no problem equalising with them:
Freediving vs scuba diving
The need to equalise is the same whether you’re freediving or using tubes. One difference between freedivers and scuba divers however, is that freedivers need to equalise quicker, since they have less time underwater and are relying on how long they can hold their breath, whereas a scuba diver can linger at various depths and take more time to equalise their ears. Also, a scuba diver could have their head upright and a free diver would probably have their head down, which can also affect how easy it is for them to equalise their ears via their Eustachian tubes.
Divers are often told not to wear earplugs. The reason for this is that an earplug seals the space between the plug and the ear drum (the outer ear) which can not actively be equalised as you can with the inner ear. So wearing earplugs doesn’t affect your ability to equalise your inner ear, as many people think, the risk however, is that because of the smaller pressure on the outer ear, the plug might be pushed into the ear canal and cause harm. What is smart (unintentionally) with SurfEars ear plugs, is that even though they don’t let any water through in normal pressure at the water surface. But as you dive deeper and the pressure increases, some water will sip through the mesh instead of the plugs being pushed in, but it is such small amounts of water that it doesn’t do any other harm. In addition, if you’re diving at low depths in situations where you are maybe just snorkelling or spear fishing, the water pressure is not likely to affect the plugs in your ears at all.
You can read reviews by divers who have tried SurfEars on the links below;