Since 1997
The Aging Diver
by DAN Medical Team on August 6th, 2016

​Nowadays there are more divers at a higher age. They are eager to savour their active time as a diver as intensively as possible. Their well-chosen dive locations often lead them to the tropics and subtropics for long periods of time. There are also more divers at a higher age, not only on diving safaris. We know that older divers rather look for enjoyment than adventure. They also dive more safely, because they are more cautious and usually very experienced. They are also more willing to act responsibly and accept restrictions regarding their diving activities in case of physical limitations.

​​Age-related physical limitations

With aging, more chronic diseases can be associated, which often leads to permanent medication. The medication must be compatible with diving. This also applies to medical aids and medical devices such as pacemakers. Here, advice from the diving doctor is required. While examining the fitness to dive he must consider typical age-related limitations to it.
  • Reduced physical fitness
  • Reduced strength and endurance
  • Altered lung function
  • Increased reaction times
  • Reduced cold resistance

Risks To The Cardiovascular System

​Already immersion itself can trigger certain physical reactions. This can have an unfavourable effect especially on older divers.
  • Fluid shift into the body core
  • Constriction of the blood vessels of the skin
  • Significant increase of urine excretion
The inevitable consequences of these immersion effects are significant fluid loss. In the elderly, this can have a particularly unfavourable effect, because they often tend to drink less anyway. Especially in summer or in (sub) tropical climates dehydration can quickly occur and cause serious diving accidents. “Thick blood” cannot properly contribute to removal (elimination) of inert gas.

These immersion effects are especially risky for the cardiovascular system. The fluid shift into the centre of the body forces the heart to suddenly pump more. If skin circulation is reduced as well, the heart has to work against an even higher resistance. Possible direct consequences are:
  • Acute hypertension
  • Circulatory disorders of the heart
  • Triggering cardiac arrhythmias
  • Acute breathlessness
Not only pre-existing heart disease may lead to serious health situations in or underwater but also increased risk of drowning as well as sudden cardiac death exist.

​​Risks For Lung and Respiration

The burden of swimming underwater is surprisingly high. This is due to the depth-dependent increased breathing gas density. The changes in the respiratory mechanics will allow for already existing health restrictions of the respiratory organs to manifest themselves suddenly. Even in experienced divers, usually less than 5% of the body energy will go to the fin. The limiting factor is the respiratory mechanics. It can quickly get out of hand with overexertion.

​​Special Attention During Medical Examination

During the medical check-up of older divers the examining diving doctor will therefore focus primarily on the function diagnostics of both cardiovascular and respiratory system, and thereby assess physical exercise capacity and endurance as well as check muscle and skeletal system. The aim is the profound advice under which conditions a diver with age-related limitations can still dive safely.

​Advice For Safe Diving At An Advanced Age

​Expand your safety margin
  • choose shorter and shallower dives
  • respect safety stops and use slow ascent rates
  • reduce repetitive dives
  • use nitrox instead of air as breathing gas
Maintain performance tolerance
  • do suitable age-adapted sports activities with focus on endurance and muscle strength
Avoid dehydration
  • sufficient hydration before diving TIP: good salivation is a sign of fluid balance
Reduce burden
  • do not challenge your physical performance limits intentionally
  • avoid stress by diving relaxed
Avoid jumping into the water
  • slide into the water to minimise the acute immersion effects
Optimise cold protection
  • the individual cold protection should be designed that even a slight chill is avoided

​Answers To FAQs of Older Divers

At what age should I reduce diving?
It is the biological age that counts, not the actual age. Starting at the age of 40 the annual medical examination for diving fitness should be more thorough and even more focussed on the “older diver” beyond the age of 55.

When should I stop going diving?
Your body will tell you. The actual age is not decisive. When it comes to health, when the body sends its own signals that diving feels burdensome or staying underwater feels unpleasant, then the time has come to reconsider.

Should I dive more conservatively?
Yes, it is strongly encouraged. There are a number of recommendations for safe diving. These should definitely be considered by older divers.

Are older divers more susceptible to decompression sickness?
Not necessarily. However, they can significantly reduce their risk of decompression illness by proper hydration before diving. Changes in the lungs at a higher age theoretically increase the risk. This risk can be reduced by ascending slowly and the use of safety stops.

Is there a greater risk of cardiovascular problems?
Unfortunately, yes. The immersion effects cannot be denied. In otherwise still compensated cardiovascular diseases they can become the straw that breaks the camel’s back, especially when unexpected events lead to sudden physical and mental stress.

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Peter Southwood - December 8th, 2016 at 2:43 AM
Interesting, though mostly pretty well established advice. One point I would like more information on is the statement: "Even in experienced divers, usually less than 5% of the body energy will go to the fin" Can you point me to the reference for this claim? This is an astonishingly low efficiency, and I would like to read up on the context. My personal experience suggests otherwise, as my effort changes significantly with the speed I travel underwater. I would guess that this refers to divers who are not trying to get anywhere, and are just casually idling around the reef, but no doubt the study will specify.
- January 11th, 2017 at 7:21 AM
For one of the very first, in-depth studies on finning efficiency, have a look at Glen Egstrom's original work in the 1960's:
Peter Southwood - January 27th, 2017 at 11:42 PM
Link does not work. What is full citation so I can search for it?
Dr Frans Cronje - January 27th, 2017 at 2:09 AM
Dear Peter,

Thank you for your meticulous reviews and comments. Other than the general references mentioned below, I have not found a specific reference using the customary search methods.

We are waiting for a response from DAN Europe and some exercise physiologists involved with DAN. As soon as we get a response, we will let you know and post it on this blog.

Again, thank you for your participation. It is what keeps the blog relevant and 'alive'! Please feel free to send any ideas you think would be appropriate to post here or even publish in Alert Diver. If you are interested, kindly send the material to

Warmest regards,


Dr Frans J. Cronje
Peter Southwood - December 8th, 2016 at 2:47 AM
How are you defining biological age, and how is one supposed to measure it?
DAN Team - December 8th, 2016 at 7:29 AM
Once again thank you for sharing your thoughts and for the questions regarding the blog post on the aging diver available via the DAN-SA website.

The following articles will more than likely help answer your questions.

"Matters of the Heart. Aging, wellness and fitness to dive", by Petar Denoble, M.D., D.Sc. (

"Cardiovascular Fitness, Diving Diet and Exercise Go A Long Way, But Watch Your Medications, Too", by Laurie Gowen. (

- January 11th, 2017 at 7:23 AM
Good comments. For an interesting article on biological vs. chronological age for cognitive ageing, have a look at this article:
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