Many of us have, at some point, experienced vertigo when scuba diving. A strange, spinning, tilting, nauseating sensation that while – in itself – isn’t dangerous, vertigo can lead to more worrying issues beneath the surface. It can also be a symptom of a more serious underlying medical issue. The PADI Open Water course briefly touches on vertigo when scuba diving, but it’s an often-overlooked safety concern. How can you prevent a bout of vertigo on your own dives?
What is vertigo, and what causes it?
Vertigo when scuba diving — a feeling of tilting and dizziness — is due to an imbalance in pressures within the left and right ears on either descent or, more commonly, ascent. Disorientation can also cause vertigo when the information your brain is receiving is dissonant to your view in the water. For example, when diving in either extremely good or extremely poor visibility, the brain can struggle to process the information presented. Disorientation and dizziness may result. Vertigo can also be a symptom of DCS, hypoxia or a contaminated air fill.
Outside of pressure variations between the two ears or mental triggers due to disorientation, the most common causes of vertigo are inner-ear infections. Diseases of the ear can also cause vertigo. Benign paroxysmal positional vertigo (BPPV), Meniere’s disease or vestibular neuritis are all possible underlying conditions. BPPV can sometimes manifest due to calcium build-up within the canals of the inner ear, causing periods of disequilibrium that may last between 20 seconds and one minute. If symptoms have presented for some time and particularly if they persist on land, consult your doctor.
Vertigo can be frightening underwater. The feeling that you’re not in control while diving can lead to anxiety and, if you lose control, potentially catastrophic consequences. Vertigo can also cause a diver to become distracted from the task at hand. Whether negotiating a wreck or drift diving in current, vertigo is something to be avoided.
As with any scuba-related problem, prevention is better (and simpler) than cure. Here are a few tips to help prevent vertigo when scuba diving.
- Stay in good condition. Don’t dive when you’re unwell or suffering from a cold or congestion that may disrupt effective equalizing on descent and ascent through the water.
- Be honest on your diving medical form. If you’re diving and answering ‘yes’ to taking prescription medications (or have any other ‘yes’ answers), obtain your doctor’s clearance before diving. Undesirable and unknown side effects may reveal themselves as vertigo-like symptoms while you’re under pressure during a scuba dive.
- Do your buddy check. Take some breaths from your tank. Does the air taste okay? If the air has a ‘taste’ – particularly if it feels heavy or oily – you may have a bad air fill. Let the dive operator know immediately.
- Stay with your buddy in-water. If something goes awry you can steady each other while you regain control.
More methods of prevention
- Use descent/ascent lines when available, especially if you’re diving in low or extremely good visibility where disorientation may be an issue. For example, if you’re descending somewhere that there will be periods of no visual reference, a reference line is a gift. Descent/ascent lines offer a tactile connection and allow you to pause a descent or ascent if the dive is not going to plan. Even if you’re quite experienced, the line is still quite useful as a visual reference.
- Equalize air spaces regularly. Disequilibrium of air spaces can be a major factor in episodes of vertigo. Go back to basics. Equalize early and often and, if you’re wearing a hood, be sure that it’s not interfering with equalization. Pull the hood away from your head as needed during descent so that you can feel the gentle water movement around your ears.
- Find visual references to help your brain become oriented. If a descent/ascent line isn’t available, look for topography, anchor lines, other divers and static marine life. Anything that offers navigational clues to your senses will help prevent symptoms. Find something to focus on.
- Mount your depth gauge or computer somewhere that you can watch your depth and position each step of the way on descent and ascent. For example, if descending onto a wreck using a line, mounting the computer on the inside of your right wrist will help. This allows you to keep the line in your right hand throughout the descent and simultaneously monitor depth and position in the water column. This also leaves the left arm free for equalizing, signaling and adjusting buoyancy.
What to do if you experience vertigo
If, despite taking precautions, you experience symptoms of vertigo mid-water, there are a few steps you can take.
- Stop, breathe, think, act. Slow down. Let your brain get some oxygen. Symptoms may subside as quickly as they arrived. Pause and take stock of the situation.
- Check your depth. Look at your computer or depth gauge. Know where you are and, if possible, maintain position. If you’re struggling to maintain focus on the figures on your computer, look for the direction of bubbles to help determine where the surface is.
- Signal your buddy for help. Not sure what signal to use? Opt for a ‘problem’ (tilted hand) and ‘narcosis’ sign (twirled finger near the temple). If you’ve been diving correctly and your buddy is close, they should be able to steady you while you regain your faculties.
- Even if you feel nauseous, keep your regulator in your mouth. Resist the temptation to rush to the surface. The regulator can cope with the vomit — it will be simply expelled through the exhaust valves. But if you remove your regulator, there is a good chance your body will instinctively inhale after vomiting, leading you to inhale water.
- If symptoms don’t subside quickly, abort the dive. If symptoms are recurring or persist on land, consult your doctor. They may indicate an underlying medical problem.
Vertigo when scuba diving is a common but infrequently discussed experience. Be prepared. Know the symptoms and what you can do to both prevent it and deal with it if it happens to you.