The essential guide to diving safely for superyachts

The changing profile of diving within the superyacht community

In the last 5 years, the role of diving within yachting has been changing.

Previously recreational diving was mostly organised by local dive companies, but as diving has become a bigger priority onboard, superyachts have started to manage their own diving activities, with a dedicated dive master.

It is also taking place in more remote locations, where hyperbaric chambers might not be as readily accessible (within 24 hours).

Given this increased undertaking, superyachts conducting their own diving, need to be more detailed within planning and prepare for worst case scenarios.

What is decompression sickness? (DCS)

Decompression sickness, or the bends, often occurs when a diver ascends too quickly from deep waters. During ascent, gas bubbles form in the body due to pressure changes.

Identifying the signs and symptoms of decompression sickness and ensuring crewmembers contact MedAire as soon as possible, is an important part of any training related to diving.

Key contributing factors of DCS include:

1. Rapid or uncontrolled ascent. As a precaution, we would advise 100% Oxygen for a minimum of one hour, as soon as possible.
2. Dehydration. Often divers will be dehydrated when the dive finishes, especially in tropical waters or extended dives. Rehydrate with a non-alcoholic, non-caffeinated drink, 1l/hour. This is important both for prevention and also treatment of DCS.
3. Pushing limits. The deeper you go, the more nitrogen you absorb, potentially putting yourself at a higher risk. The divemaster should set realistic parameters. Be conservative and aim for shallow, short dives. A good rule of thumb is:
• No deeper than 18m
• 30-45 minutes per dive
Some estimates suggest around 80% of everything you can/will see underwater is within the first 20 meters, which further highlights the need to set reasonable parameters.
4. Undiagnosed Patent Foramen Ovalé (PFO) (a hole in the heart)

Promptly recognising risk factors and administering oxygen before symptoms appear can help prevent severe decompression sickness (DCS). By the time symptoms manifest, gas bubbles may have already formed in the body, reducing the effectiveness of oxygen. Awareness and prevention play crucial roles in avoiding DCS.

Medical Equipment for diving

Oxygen

Always ensure an adequate Oxygen supply at the dive site

• Minimum quantity: One hour/per person. On top of that (preferably) enough to also get you back to the vessel.

Using the demand valve is the most efficient way of taking in Oxygen because it provides oxygen only during inspiration, eliminating wasteful oxygen delivery during exhalation. This is provided within our Global Oxygen Kit.

How to work out duration of Oxygen: Volume of cylinder (L) x pressure in cylinder (bar) / flow rate (L/Min) = TOTAL DURATION

Oxygen Concentrator

For vessels frequently diving, MedAire would always recommend to have an Oxygen concentrator onboard, providing an unlimited supply of Oxygen.

Hyperbaric Chambers

If you are concerned about someone after a dive, contact MedAire immediately, we have specialist dive doctors available to consult. If the patient is showing neurological signs, you will need specialist medical care, which may include a hyperbaric chamber.

For minor signs and symptoms, Oxygen will be recommended, for an extended period of time. Often there will be an ‘air break’ every hour to reduce the deleterious effects of Oxygen and provide fluids to the patient. Discontinue if no further signs of illness.

You can also use MedAire’s DCS quick card to help guide the patient assessment.

Do I need a hyperbaric chamber?

MedAire help guide many clients through this decision and provide new build consultancy on medical room and hyperbaric chamber suitability onboard superyachts.

Considerations can include:

• The remoteness of the diving
• The type of diving
• Space on the vessel

MedAire, superyachts & Diving

From prevention through to case management, MedAire provide invaluable expertise when it comes to diving:

• Prevention: MedAire clients have dive specialist doctors on call that you can consult with to discuss your specific requirements. They will listen to your diving profiles and put protocols in place to mitigate risks, pre-travel.
• First Response: Specialist dive doctors are available 24/7 to help assess the patient and guide difficult decisions.
• Case Management: We maintain a network of hyperbaric chambers to help you navigate to the nearest location, if a patient requires decompressing.

Our team also understand the specifics of diving, whether that’s the difficulty of evacuation by plane (for many aircraft, that is flying no more than 1,000 feet above sea level, which limits the flight path, potentially having to go around mountains instead of over, for example) the training level of crewmembers or the equipment you have onboard – we can be trusted to support your diving operations.

Contact us here.