What are the issues with Covid-19 and safe diving?
The coronavirus pandemic sweeping the world has changed the way many of us live. Leisure pursuits have largely been suspended, people are encouraged to keep at least 2m apart and avoid physical contact wherever possible. The usual behaviour for recreational diving is in buddy pairs and both rely on each other to assist when needed and maintain close contact. Therefore, when will recreational diving be possible, advised or need to be modified before divers can resume their passion?
It is now well known that Covid-19 can seriously damage the lungs and heart. For those that survive Covid-19 (probably 98% of those infected) we do not know yet how many will have permanent significant damage and how many will only have temporary damage, but for an unknown duration.
Lung damage is a significant risk factor for pulmonary barotrauma on ascent in the water. The lung damage may also increase the risk of developing a right-to-left shunt leading to decompression illness in a similar manner to those with a Patent Foramen Ovale (PFO.)
Heart damage may increase the risk of developing cardiac arrhythmias and myocardial infarction underwater. It may also lead to a decompensation with exercise causing hypoxia.
Many of these reports are only anecdotal, in that they have not been properly reported in peer-reviewed medical journals. However, these publications take many months to achieve and the absence of this recommended evidence is not an indication that these problems are not occurring! Therefore, our normal policy of basing medical advice on ‘evidence’ is inappropriate unless we are to recommend cessation of all diving activities until the journals catch up.
This advice is based on UK and International guidance, personal experience, anecdotal reports, internet reports and hopefully a degree of common sense.
Non-peer-reviewed internet reports suggest that 40-80% of people who report not having had any Covid-19 related symptoms may have actually had a mild form of the illness without realizing it. Therefore, in the absence of any specific test confirming the person has never had the illness (? antibody testing) then we should assume that everyone has potentially been infected or maybe infectious.
Dr Frank Hartig, an Austrian physician reported on Wetnotes that of the many patients that he had treated 6 were divers. None were admitted to hospital and were sent home to self-treat. He reviewed them 6 weeks later when all reported that they were well, clinical examination was normal. However, he referred them for CT scans and 4 had serious lung damage. 2 had developed a reactive airways disease (asthma like) and 2 became hypoxic on exercising. Further follow up has not yet occurred so we do not know if this is temporary or permanent. This tells us that even though with supposed mild illness, that does not require hospital treatment, significant lung and heart disease may develop which would be dangerous for diving.
Guidelines for the medical assessment of divers post Covid-19
As the Coronavirus pandemic progresses there are lots of reports of significant lung and heart damage being observed in survivors.
Significant online reports relating to this are available at:
1) Dr Frank Hartig’s case series - https://www.wetnotes.eu/tauchen-nach-covid-19-erkrankung/
2) Belgium Society of Diving’s guidance on assessing divers – 12th April 2020 http://www.eubs.org/wp-content/uploads/2020/04/2020-0412-Position-of-the-BVOOG.pdf
UC San Diego Guidelines
for Evaluation of Divers during COVID-19 pandemic – 8th
European Underwater &
Baromedical Society’s guidance on assessing divers – 21st
5) UKDMC guidance -
30th June 2020.
The UKDMC have decided to take a cautious approach to recommending fitness to dive in relation to proven, suspected or symptoms compatible with Covid-19 infection. They recommend using a scorecard to assess risk, but even with a score of Zero they believe the risk of lung changes to be 5% due to having had an asymptomatic infection. Therefore, all divers will need to accept this potential risk. Diving abroad will, therefore, be of considerable risk as many, if not all, of the insurers will not provide assistance for Covid-19 related problems. Any diver who has needed hospitalisation for Covid-19 symptoms is rated as very high risk and should not return to diving for at least one year, and then only after full assessment. Anyone else who has had one or more of the potential symptoms of Covid-19 since January 2020 (fever, cough, shortness of breath, loss of taste or smell) should not dive for at least 3 months following return to full health and exercise capacity, and after full assessment by a diving doctor. Hence all divers need to review their need to see a diving doctor for assessment and what level of risk they find acceptable.
This is my review and is for
information only. All divers should read the guidance for themselves
and decide what is applicable to them. Divers presenting
to myself for advice will have individual medical and risk
Divers presenting to myself for advice will have individual medical and risk assessments.
Covid-19 screening algorithm:
Since January 2020 have you had any symptoms suggestive of Covid-19 infection?
(See below for symptoms)
□Go to Q2
□Go to Q3
Have you had a positive test for Covid-19?
□Go to A
□Go to Q3
Have you been admitted to hospital or been treated with supplemental oxygen?
□Go to B
□Go to Q4
Have you needed respiratory support e.g. ventilation?
□Go to C
□Go to D
Possible symptoms of Covid-19:
· Fever / chills
· Loss of appetite
· Cough / shortness of breath / sore throat
· Muscle pain / aches
· New loss of smell or taste
Advice of when to resume diving and what tests may be needed:
A – Although you are at low risk you may have had an asymptomatic infection. Refrain from diving for 1 month (I recommend July 2020 earliest.)
B – Refrain from diving for 1 month from date of diagnosis. Spirometry and exercise tolerance test with oxygen saturation monitoring recommended.
C – Refrain from diving for at least 3 months after resolution of symptoms. Spirometry, High resolution CT of lungs and exercise tolerance test with oxygen saturation monitoring recommended.
D – Refrain from diving for at least 3 months after full recovery. Advised full assessment by both Respiratory and Cardiology specialists.
Only spirometry was included in the Pre Covid-19 medicals, all other tests will be at additional cost.
The UK remains under lockdown, although it is being eased.
Social distancing is still required. Medical assessments require
close contact. Spirometry and exercise testing result in powerful
exhalations that will allow respiratory droplets potentially
infected with coronavirus to be spread rapidly. Therefore these
assessments are high risk.
The UK remains under lockdown, although it is being eased. Social distancing is still required. Medical assessments require close contact. Spirometry and exercise testing result in powerful exhalations that will allow respiratory droplets potentially infected with coronavirus to be spread rapidly. Therefore these assessments are high risk.
Charts below are from The Oxford Martin School of The
University of Oxford's Our World in Data website:
Charts below are from The Oxford Martin School of The University of Oxford's Our World in Data website:
Although the number of Covid-19 cases in the UK fell to less than a
1,000 per day, unfortunately the number of cases is once again
Therefore, it should be
remembered that there is still a significant risk of transmission of the
Coronavirus during any close contact. These
medicals will still need to be conducted with PPE and disinfection
protocols so there will be a surcharge of £25 per medical to cover
these additonal costs. More information on having a medical with
Therefore, it should be remembered that there is still a significant risk of transmission of the Coronavirus during any close contact. These medicals will still need to be conducted with PPE and disinfection protocols so there will be a surcharge of £25 per medical to cover these additonal costs. More information on having a medical with Covid-19 protocols.
The recommencement of this service is not an endorsement that it is safe to dive, you should only resume diving if your risk assessment is satisfactory and acceptable to all concerned.
Updated 10th September 2020
Updated 10th September 2020