Understanding the impact of a Covid-19 infection on diving
A history of COVID-19 should be a significant factor to consider when establishing if somebody is fit to dive, especially considering the underwater and hyperbaric environment and physiological demands of diving. Existing published studies have shown that there are structural lung changes following a COVID-19 infection. These changes have the potential to lead to areas of gas trapping, increasing the risk of pulmonary barotrauma.
As well as this, any ongoing symptoms of COVID-19 (i.e., ‘long covid’) are likely to effect aerobic fitness and exercise capacity which may make it more difficult to cope with physical demands such as strong currents or an emergency.
We know that damage to the lungs can last for a long time after the initial infection and it is important that divers are back to their normal level of fitness with no evidence of hypoxia (low oxygen) on exertion before they get back in the water.
Last year we asked divers to fill in an online survey regarding COVID-19. Our aim was to understand the prevalence of infection amongst divers who were planning on returning to diving after infection and if they had any residual symptoms which could potentially affect their fitness to dive.
In essence, the key messages are as follows:
- There are potentially large numbers of UK divers with ongoing symptoms following their COVID-19 illness.
This raises a significant question as to when these divers will be safe to return to diving and how to assess this. Evidence on which dive doctors can base fitness to dive advice is scarce and makes it difficult to give informed advice.
- Despite not having full resolution of symptoms, a significant percentage (63%) of those with non-hospitalized COVID-19 infection still felt ready to return to diving.
This raises concerns; primarily about the understanding of the risks of diving with ongoing COVID-19 symptoms, but also about returning to diving after a significant illness without advice from a dive doctor.
Overall, our survey has shown that many UK divers have not only had the COVID-19 infection but are having ongoing residual symptoms. Caution about returning to diving should be promoted due to known risks and divers must speak to a dive doctor before getting back into the water.
What are the guidelines?
The understanding of COVID-19 disease pathology and the long-term effect on the body is still limited. As the number of people returning to diving after having a COVID-19 infection start to increase it is important that divers seek fitness to dive medical advice.
For recreational divers the UK Dive Medical Council (UKDMC) provides the fitness to dive guidelines. The guidelines for covid can be found here: Coronavirus / Covid-19 – UKDMC.
In summary, if you have had a positive covid test, even if you were asymptomatic, there is still a risk of underlying damage to your lungs. The guidelines state that you must not dive for 3 months. After this period, you must have an exercise test with pulse oximetry, this is to check that your oxygen levels do not decrease when you exert yourself. This test must be done with a UKDMC dive referee. It is likely that as we understand more about the impact of COVID-19 on the diving community then this guidance will be updated.
For commercial divers the UK Health and Safety Executive (HSE) govern the rules regarding fitness to dive. Their guidelines can be found here: Extension for diver’s certificate of medical fitness during the coronavirus pandemic – HSE news.
If in doubt, please speak to your local dive referee/AMED or you can speak to one of our doctors by booking a Fitness to Dive telephone consultation.
Please note: Safety is our priority; therefore, our advice will be based on the guidance listed above. We appreciate it is frustrating when this interrupts your diving plans!
With thanks to: Dr Rosie Stokes, Dr Ashley Davies, Dr Ross Sayers and Dr Megan Evans for their significant contributions.