The 2021 tragedy aboard the HMS Scylla remains one of the most sobering reminders of the risks inherent in technical wreck diving. This incident serves as a case study for the diving community, emphasizing that experience does not grant immunity to the physical realities of silt-outs and confined spaces.
Read The Scuba News Article on the HMS Scylla
Below is a summary of the events and the critical survival details as recounted by Adam Dent::
The Incident: A Routine Dive Gone Wrong
On September 3, 2021, three highly experienced divers—Andrew Harman (40), Mark Gallant (49), and Adam Dent (then 24)—ventured into the interior of the HMS Scylla, a former Royal Navy frigate sunk as an artificial reef off Whitsand Bay, Cornwall.
While four other divers explored the exterior, the trio planned a “penetration” dive to the ship’s third deck—a known high-risk area due to its age and heavy silt accumulation.
The Critical Turning Point
The disaster was fueled by several factors that converged in a matter of minutes:
- Zero Visibility: As the divers moved through the engine room area, the fine silt on the floors was kicked up, creating a “brown-out” that reduced visibility to absolute zero.
- The Absence of a Guide Line: Contrary to standard overhead environment protocols, no physical line was laid to the exit. Without a line to follow by touch, the divers became hopelessly disoriented.
- The Dead End: In the confusion, the group ended up in a dead-end corridor. Adam Dent describes the moment of realization as one of total isolation; in the pitch black, he lost all visual and physical contact with his companions.
Adam Dent’s Survival
As his air supply dwindled and the reality of the situation set in, Dent was forced to make a series of high-stakes decisions:
- The “Black Blob”: While engulfed in the silt cloud, he spotted a faint change in light—a “black blob” above him.
- The Narrow Escape: The opening was a small cut-out in the ship’s structure, partially blocked by bars.
- Doffing Equipment: To fit through the narrow gap, Dent had to remove his twin-set cylinders underwater while maintaining his regulator in his mouth—an incredibly difficult task under extreme stress. He managed to squeeze through and reach the surface just as his air ran out.
The subsequent inquest and Dent’s recent reflections offer vital takeaways for wreck divers:
Hazard Lesson Learned
Silt-Outs
Even the most familiar wrecks change over time as they decay; silt is a progressive and deadly risk.
Protocol
Experience can lead to complacency. Always use a continuous guide line to open water when entering any overhead environment.
Equipment
Proficiency in “gear manipulation” (removing and replacing kit underwater) can be the difference between life and death in an entrapment scenario.
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