Why do I feel panicky when descending underwater?

You know that you want to go scuba diving, and put a lot of time and effort into getting ready for the dive. You were excited about getting back under the water and looking forward to what you might see. But, when you see the thumbs down signal and go to press your deflate button, you suddenly find it really hard to let yourself slip under the surface. Nerves and anxiety take over and you start to feel a bit panicky when descending underwater. But, you REALLY want to go for a dive – so why is this happening? and what can you do about it?

Reasons new divers might feel panicky when descending underwater

It’s not natural

Humans can’t breathe underwater, not without our scuba diving equipment. So the human brain has developed safety mechanisms to stop us from drowning. It’s almost like we have an in built alarm that goes off when we sink under the water and try to continue to breathe. Our brain is screaming “no, don’t do that!” “swim up!” “get out!” It tries to keep us safe by triggering all sorts of reactive behaviours and sending messages around the body through nerves and hormones. This is the fight or flight reaction, and it’s not very helpful if we want to go for a nice relaxing dive.

Our body is doing stuff that makes it worse

Due to all these messages the brain is sending around the body, we end up doing stuff that makes it harder to descend. First, we instinctively hold our breath. With our lungs full of air we are more positively buoyant, and so we are still floating! Secondly, our legs start doing a weird running motion. This is called the mammalian swimming reflex, and it is an automatic, anti-drowning behaviour. You may not have noticed this yet, its a reflex behaviour and we are not always aware we are doing it.

On the first few open water dives, it’s pretty common. The diver complains that they are trying to descend but are not going anywhere. The guide takes a look under the water and sees the diver’s legs are doing this running motion. (It isn’t proper swimming, it looks more like stepping, like the persons it climbing the water). The guide says “stop swimming” – the diver says “I’m not!” This is because the reflex is so automatic we do not know we are doing it.

To understand the mammalian swimming reflex, check out videos of dogs swimming out of the water! (But remember to come back, as there are some tips below!) The videos show how this reflex can be triggered easily by sensations caused by being on, or over, water. Here are a couple:


The stuff our body is doing convinces our brain that something must be terrible wrong!

Not only do our brains send out messages to the body, they listen to the messages that come back! They read these messages to find out what is going on in the world, so that they can send more messages to tell our bodies what to do about it. Sometimes this causes confusion, because the brain doesn’t always interpret the message correctly.

The way the brain works out what is happening is to look at the messages coming from the senses, and the information it already has stored in memory. Your brain doesn’t have much information about scuba diving at first, so it might freak out a bit. Even though in your mind you understand that it will work, the brain may take a while to catch on. So, when we first try to scuba dive it often goes a bit like this:

Brain giving orders

Brain > lungs: “looks like were are sinking under the water, hold your breath!”

Lungs > Brain: “still sinking, you know, I can sort of breathe, …”

Brain > lungs: “no, my information here tells me we can’t breathe underwater, inhale hard and keep as much air as possible”.

Lungs > Brain: “hey, this is hard work”

Heart > Brain “erm, I’m working really hard here too, what the *%?! is going on out there?!”

Brain > Heart: “I dunno! Could be pretty bad, pump harder!”

Mind > Brain: “hey, guys, it’s okay, I just want to go under water, I’ve got this special kit and everything!”

Brain > Mind: “Shut-up! we are busy trying to save you!”

Our brains are connected in with all the senses, and also get feedback from the internal organs. So, part of the reason you might feel panicky when descending underwater is that your brain is picking up on tense muscles, lots of air held in lungs and a fast heart beat. It can’t work out what is going on, and it speeds that all up to build the fight or flight reaction. It’s a survival mechanism, but if it gets out of control it can spiral into panic.

Maybe there is actually something wrong

It is important to remember, that maybe your brain has a good reason for trying to stop you go under the water. Maybe it knows there is something that you are not really ready for. What are the conditions like? Have you missed something? Did you do a proper buddy check? How do you feel about the people you are diving with? Have you developed the skills you need for the dive you are about to do?

Things to feel less panicky when descending underwater

Let your brain and body know it’s okay

Allow yourself to exhale. Release the air from lungs. Remind yourself to do it again and again, as your brain might want to keep filling the lungs.

Keep feet still and pointing down. Relax, allow yourself to sink.

Dive. The more you dive, the more information your brain can gather from the experience and the more comfortable it gets. It will eventually stop shouting orders to breath-hold and run.

Evaluate the situation

This can be really hard, because you don’t know what you don’t know. As a new diver, you have no references, so it can be hard to work out if the conditions, plan and dive are okay. Also, we all vary in how we assess risk, so you just have to gather the information you can and decide what you think.

Evaluate the situation before and during the dive. This can mean things like checking out the reviews for the dive centre, asking about their safety procedures. Even your gut feelings about the situation and people.

Check your thoughts. Is it all unhelpful worries? Or is there something that your brain is trying to draw your attention to?

Learn and keep learning and you’ll gradually stop feeling panicky when descending underwater

If your brain knows you can handle a situation it will calm down and let you handle it. In diving that means learning the various skills you need to dive safely.

What is your buoyancy and finning like? Are you developing your ability to position yourself in the water – is this particular dive site a good match for your current skill, or do you need something else? Maybe going back the shallows or swimming pool. Perhaps booking time with an instructor or personal guide for advice and safety. It’s possible to practice descending underwater in 2 or 3 metres, do it over and over and it will start to feel easier as you gain the skill and your brain starts to grasp that you can do this.