The essential guide to diving safely for superyachts

The changing profile of diving within the superyacht community

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

Previously, recreational diving was mostly organised by local dive companies. As diving has become a bigger onboard priority, superyachts increasingly manage their own activities with a dedicated divemaster.

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

Given this, superyachts conducting their own diving need to plan in more detail 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 depth. During ascent, gas bubbles can form in the body due to pressure changes.

Identifying signs and symptoms of DCS and ensuring crewmembers contact MedAire as soon as possible is an important part of any diving-related training.

Key contributing factors include:

1. Rapid or uncontrolled ascent. As a precaution, administer 100% oxygen for a minimum of one hour as soon as possible.
2. Dehydration. Divers are often dehydrated post-dive, especially in tropical waters or after extended dives. Rehydrate with a non-alcoholic, non-caffeinated drink at ~1 L/hour. This is important for both prevention and treatment of DCS.
3. Pushing limits. The deeper you go, the more nitrogen you absorb, increasing risk. The divemaster should set realistic parameters. Be conservative and aim for shallow, short dives:
   • No deeper than 18 m
   • 30–45 minutes per dive

   About 80% of what you can see underwater is within the first 20 m, reinforcing the value of conservative profiles.

4. Undiagnosed Patent Foramen Ovale (PFO).

Promptly recognising risk factors and administering oxygen before symptoms appear can help prevent severe DCS. By the time symptoms manifest, bubbles may already have formed, reducing oxygen’s effectiveness. Awareness and prevention are crucial.

Medical equipment for diving

Oxygen

Always ensure an adequate oxygen supply at the dive site.

• Minimum quantity: one hour per person, plus preferably enough to return to the vessel.

Using a demand valve is the most efficient way to deliver oxygen, as it supplies oxygen only during inspiration, avoiding waste during exhalation. This is provided in our Global Oxygen Kit.

Calculating oxygen duration: Volume (L) × Pressure (bar) ÷ Flow rate (L/min) = total minutes.

Oxygen concentrator

For vessels diving frequently, MedAire recommends an onboard oxygen concentrator for an effectively unlimited supply.

Hyperbaric chambers

If you are concerned about someone after a dive, contact MedAire immediately; specialist dive doctors are available to consult. If the patient shows neurological signs, specialist care may be required, including a hyperbaric chamber.

For minor signs and symptoms, oxygen is typically recommended for an extended period, with hourly air breaks to reduce oxygen toxicity and to provide fluids. Discontinue if no further signs of illness.

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

Do I need a hyperbaric chamber?

MedAire helps clients make this decision and provides new build consultancy on medical room and hyperbaric chamber suitability onboard superyachts.

Considerations include:

• Remoteness of diving
• Type of diving
• Available space on the vessel

MedAire, superyachts, and diving

From prevention through to case management, MedAire provides expertise for diving operations:

• Prevention: Dive specialist doctors on call to discuss your profiles and put protocols in place to mitigate risks pre-travel.
• First response: Specialist dive doctors are available 24/7 to help assess patients and guide difficult decisions.
• Case management: We maintain a network of hyperbaric chambers and help navigate to the nearest facility if decompression is required.

Our team understands diving-specific constraints, from evacuation by plane (often limited to flying below ~1,000 ft, affecting routing around terrain) to crew training levels and onboard equipment. We can be trusted to support your diving operations.

Contact us here.