If you’ve ever experienced ear pain or trouble equalising the pressure between your ears during a diving ascent, then you’ve likely experienced reverse block. Unlike ear squeeze, which happens on the descent, reverse block is experienced by divers during an ascent, and should be dealt with in its own way.

There are many reasons why reverse block might happen, and divers can often be confused as to why they’re having trouble equalising on the way up when they had no problem doing it on the way down. In this article we’ll go into detail about what reverse block is, what’s happening inside the body, and what you can do to prevent it from occurring.

In an ideal world, this is stuff that’s covered in your diving course – information told to you once, that you retain and never forget. But this world isn’t ideal and people forget things and need a refresher, including the team at Ninja Shark! Consider this your refresher on reverse block dear divers, and stay safe out there.

What exactly is reverse block?

OK so first thing’s first, it’s not an ear squeeze. Ear squeeze is the result of failing to equalise pressure on the way down, and is a lot more common and can have more negative implications for the diver. Reverse block, on the other hand, happens on the way back up, and luckily leads to less revolting results!

What happens when we get reverse block?

You already know that as you dive deeper underwater, the pressure in your surrounding environment increases. That means there’s more pressure being applied on our body, and you can feel those pressure changes as you dive further down. You equalise your ears and you’re all good.

On the way up, however, the air that’s inside your body begins to expand. Usually, that air should seep through your bloodstream and into your tissues, releasing with your exhale. Reverse block is what happens when that expanded air is trapped inside your ears and cannot be released. That trapped air begins to exert its own pressure, causing ear pain that’s quite similar to the sensation of ear squeeze.

Unlike ear squeeze however, this pain is due to having too much air between your ears rather than too little. And for that reason, you need to deal with it differently. In fact, the worst thing you could do is react to reverse block as if you have an ear squeeze, by blocking your nose and exhaling. You’ll just be adding more air to your already-full ears!

What do I do if I experience reverse block?

It may be instinctual for you to equalise your ears by pinching your nose and blowing, but whatever you do, don’t! If you’re feeling reverse block, there are three main courses of action to take:

  1. Sit back and relax – Stay where you are and wait for the pressure to ease off on its own. Stop your ascent, and give your body some time to release that extra air pressure between your ears. The key point is to relax here and not feel tense as that can have the opposite effect.
  2. Dive down again – Descend back down a few metres until you stop feeling the reverse block. The increase in water pressure can re-shrink your trapped air bubbles, decreasing the pressure. You can then continue your ascent at a slow pace, giving your ears time to release the pressure.
  3. Take your time – This option isn’t available to everyone, but if you have enough air left in your tank, then take it slow going back up. Reverse block can sometimes take up to 10-15 minutes to ease off, so be patient and always start your ascent while you’ve still got plenty of air in the tank. Running out of air during your ascent means you may be forced to go up without treating your reverse block, risking ear barotrauma.

How to prevent reverse block

The good news is that most cases of reverse block are preventable, and when it does happen, it’s usually due to naughty divers ignoring safety guidelines! That’s okay though because not everyone will be following the rules 100% of the time.

The most common causes of reverse block is sick divers using decongestants and other sinus relief medication to help them equalise on their way down. What they don’t know is that drugs are metabolised much faster underwater, meaning that by the time they’re ready to go back up, those decongestants have worn off and are no longer effective. Without the medication unblocking their nose, the air becomes trapped between the ears, leading to reverse block.

You can also experience reverse block if you are diving with an ear infection. Stick to the following rules and you should hopefully never experience reverse block:

  1. If you have chronic sinus issues, don’t dive unless you’ve been checked by a dive doctor,
  2. Never ever go diving with a cold, flu, or headache,
  3. If you do take decongestants, make sure that they won’t have worn off halfway through your dive.

Do earplugs help when diving?

There are a lot of different opinions out there when it comes to using earplugs while diving. While the Divers’ Alert Network does state that they’re generally not recommended, it is noted that they can be used in special situations under special considerations.

What earplugs should I buy for diving?

The key point when looking to buy earplugs for diving is to purchase vented earplugs, which have a small hole that allows for venting between the water and the ear canal. These holes allow equalisation to occur without letting water into your ear canal. According to manufacturers of these vented earplugs, they can even make equalisation easier and more effective.

When should I use earplugs for diving?

While manufacturers claim the effectiveness of their earplugs for diving, there’s a lot of conflicting information out there and a lot of divers have reported unpleasant experiences using earplugs. To us, we think earplugs should be used only to keep water out of your ear and not to make equalisation ‘easier’ or ‘better’. There’s no real evidence to support claims that earplugs can make equalisation easier, and we don’t want you to rely on them to help you balance pressure when diving.

There are also many issues which you could face if the vent became clogged with wax or if the earplug fell out of your ear. In our opinion, earplugs are great for external ear infections or surfer’s ear, but if you’ve got sinus congestion or you’re looking to make equalising easier, then don’t rely on earplugs to be the magic solution. That said, plenty of divers out there have experienced success, so you do you…