El Salvador, El Salvador
90m
8m - 23m
Boat
Advanced
Deep, Drift, Reef, Rock, Shark
Boat
90m
8m – 23m
Advanced
—
-1% at 88m / 21%
O2Gradual Narcosis Onset — Narcosis may develop slowly, making self-assessment unreliable.
Task Fixation at Depth — Cognitive narrowing at depth can reduce awareness of time and ascent rate.
Increased Gas Density Breathing Load — Higher gas density at depth increases work of breathing.
Eddy Pull-Off Zones — Eddies behind structures can pull divers away from the main drift line.
Delayed Surface Pickup — Strong current can exceed surface tracking assumptions, delaying boat pickup.
Vertical Current Shear — Currents may vary by depth, causing vertical separation even when divers stay together.
Hidden Depth Variations — Complex reef topography can conceal depth changes, leading to unintended profile variations.
Distraction from Marine Activity — High fish activity can distract divers and delay depth or gas awareness.
Rapid Surge Direction Changes — Surge near reef structures can reverse direction quickly, pushing divers sideways into unexpected areas.
Bubble Trapping Under Overhangs — Rock overhangs can trap exhaled bubbles, reducing visibility and causing disorientation.
Reflected Surge Patterns — Surge reflecting off rock faces can create irregular and unpredictable water movement.
Current Funnel Effect — Narrow gaps between rocks can accelerate water flow unexpectedly.
Situational Awareness Loss — Divers may fixate on sharks and lose depth or position awareness.
Subtle Behavioural Shifts — Changes in shark behaviour may be missed without active observation.
Blue-Water Reference Loss — Lack of visual references increases ascent and descent instability.