Darker cells mean a higher score for this topic on that metric.
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Quick answers
Which local rescue or training agency should I check first?
Use the local lens: coastguard/federation norms and the shop briefing for that bay — not a blog visibility claim.
Why is risk scored so high here?
Silt, entanglement, lost exits and the urge to “just look inside” show up in fatality reports. Night-plus-wreck is worse.
What is the Yongala?
A 1911 passenger steamer off Queensland, now a protected historic wreck and a famous GBR dive — typically exterior.
What is the Thistlegorm?
A 1941 British cargo ship bombed in the Red Sea, rediscovered by Cousteau’s team in the 1950s, now a mass recreational wreck.
Are wrecks war graves?
Many are. Touching remains or souvenirs is illegal and indecent.
Do people need trimix?
Not for typical recreational wreck exteriors. Deep technical wrecks are another sport.
Wreck fatalities cluster on penetration without a line, entanglement, and depth plus narcosis. This is not a briefing and not medical advice.
If the exit is not obvious, the dive is already an overhead dive.
Hazards
- Lost exit — Silt or a wrong turn in a hold.
- Entanglement — Nets, lines, and collapsed structure.
- Unstable wreckage — Storms rearrange ships.
- Sharp metal and hydroids — Infections, not folklore.
- Depth and narcosis — Many famous wrecks sit deeper than OW limits.
- Unexploded ordnance — Especially war wrecks. Do not touch.
Rules
- No untrained penetration — The whole rule.
- Treat war graves as graves — No souvenirs, no posing with remains.
- More gas than a reef dive — The exit may be slower.
- One wreck, one plan — Do not “add a hold” mid-dive.
- Local permit and brief — Always.
Red flags
- A guide who says the hatch is fine for OW — Walk.
- Silt starting and the group still entering — Turn.
- A missing line in an overhead — The dive is over.
- Someone pocketing a relic — The park’s problem and a safety problem (time, cuts).
First response
- Follow the line out — If there is no line, the plan already failed — surface if you still can, boat, emergency services.
- Entanglement — Stop, think, cutter. This is not a protocol page.
- Not medical advice — DCI and trauma are clinical.
Wreck safety is a line and a no. Curiosity is how holds become rooms without exits.