Fatal Accident in Vietnam: DCS & Rapid Ascent — What Happened, Symptoms to Know, How to Avoid It, and What To Do
- Cuddlefish Divers
- Oct 1
- 4 min read
On 24–25 September 2025, Vietnamese and international outlets reported a tragic incident off Quang Tri Province, central Vietnam: two recreational divers surfaced abruptly from ~15–20 m; both developed suspected decompression sickness (DCS). One diver died; the other was transferred for hyperbaric treatment in critical condition.
This article explains—in plain language—what DCS is, how rapid ascents trigger it, the symptoms you should recognise, how to reduce your risk, and what to do if it happens. It closes with an action checklist and resources we use at Cuddlefish Divers to keep our community safer.
What is DCS (Decompression Sickness)?
DCS is a diving injury caused by inert gas (mostly nitrogen) coming out of solution and forming bubbles in tissues and blood during or after ascent. Rapid ascents and inadequate decompression are classic triggers. Immediate oxygen first aid and timely recompression (hyperbaric oxygen therapy) are the standard of care.
Why rapid ascents are dangerous
Ascending too fast reduces ambient pressure faster than your body can safely off-gas dissolved nitrogen. Microbubbles can expand and coalesce, obstructing blood flow and irritating tissues—especially in the joints, spinal cord, brain, and skin. In severe cases, lung overexpansion can also cause arterial gas embolism (AGE), an immediate life threat requiring urgent recompression. Early treatment matters: good practice guidance targets treatment as soon as possible—ideally within hours.
Symptoms of DCS (what divers and buddies must watch for)
Treat any of the following after diving as DCI/DCS until proven otherwise:
Pain: deep, aching joint or limb pain (“the bends”), back pain.
Neurological signs: tingling, numbness, weakness, imbalance, difficulty walking, urinary retention, confusion, visual changes.
Skin signs: marbling (cutis marmorata), itching, mottling, swelling.
Constitutional: unusual fatigue, dizziness, headache, shortness of breath, chest pain.
Severe / red flags: paralysis, loss of consciousness, severe breathing problems—treat as an emergency immediately.
Key teaching from DAN and hyperbaric references: Do not “wait and see.” Oxygen first aid and calling for expert help early improves outcomes—even when symptoms seem mild or come and go.
How to reduce your risk of DCS (evidence-based habits)
Before you dive
Be fit to dive: Declare medical issues honestly; obtain physician clearance if indicated (many operators require it).
Plan your profile: Conservative no-deco limits, deep-to-shallow profile, proper gas planning.
Use a reliable computer, set conservative gradient factors/safety settings, and enable ascent-rate alarms.
Hydrate, rest, and fuel sensibly; avoid alcohol and intense exertion pre-/post-dive.
During the dive
Ascend slowly: ≤9–10 m/min as a rule of thumb and follow your computer. Add a safety stop (3–5 min @ 5 m) even on easy dives.
Control buoyancy: Avoid “yo-yo” profiles and runaway ascents; vent gas early and often.
Watch your workload and temperature: Heavy exertion and being cold can increase DCS risk for a given profile.
After the dive
Respect surface intervals (longer after deeper/longer dives).
Delay altitude exposure (flying, high mountain travel) per computer/DAN guidance.
Listen to your body: Any unusual symptom after diving is DCI until assessed.
(For a readable refresher on mechanisms, first aid priorities, and why denial is dangerous, see Mark Evans’ diver-focused overview.)
What to do if DCS is suspected (first-aid algorithm you can memorise)
Stop diving. Stabilise the diver at the surface.
100% Oxygen ASAP: Use a non-rebreather mask or demand valve with the best possible mask seal and flow; keep SpO₂ high while awaiting evacuation.
Call for help early: Activate local EMS. Contact DAN emergency line for dive-medicine advice and chamber coordination (+1-919-684-9111 worldwide).
Position & care: Keep the diver warm, lying flat and comfortable; do not give nitrox via scuba, do not recompress in the water unless you are part of a trained, properly equipped team following formal protocols (this is rarely appropriate recreationally).
Hydration: If conscious and not vomiting, small sips of oral fluids are reasonable unless contraindicated.
Monitor: Reassess neuro signs frequently; document onset times and changes (use a simple neuro exam checklist if trained).
Rapid transfer to hyperbaric care: HBOT (recompression) is the accepted treatment for DCS/AGE and should be delivered as soon as feasible.
Lessons from the Vietnam case
Depths were recreational (15–20 m), yet an abrupt/rapid ascent was reportedly involved—a reminder that you don’t need to be deep or in deco to suffer DCS.
Time to treatment matters. The surviving diver was transferred for hyperbaric oxygen therapy—consistent with international best practice.
Take symptoms seriously, immediately. Early oxygen + call for expert help saves lives.
Quick DCS prevention checklist (print/share with your buddy)
✅ Pre-dive medical honesty; carry required medical statement.
✅ Conservative computer settings; ascent-rate alarms on.
✅ Buoyancy dialled in; slow, steady ascents; mandatory safety stop.
✅ Post-dive: rest, hydrate, avoid strenuous effort and flying too soon.
✅ Boat/club 100% O₂ kit maintained and ready; team trained to use it.
✅ Know the local chamber/EMS contact plan; save DAN Emergency number.
For Singapore & regional divers
Hyperbaric oxygen therapy (HBOT) is the standard treatment for DCS/AGE, delivered in dedicated recompression chambers by trained teams. If you dive regionally (e.g., Vietnam, Malaysia, Indonesia), plan evacuation routes before you splash.
Final word on DCS
DCS is uncommon, but it is preventable. Slow ascents, conservative planning, and decisive oxygen-first aid are the difference between a scary story and a catastrophe. The Vietnam tragedy underscores that even “easy” dives demand disciplined ascent and buddy awareness.
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