Gradual 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.

Landmark Misidentification — Familiar sites can become unrecognisable at night.

Light-Induced Tunnel Vision — Focused light beams reduce peripheral awareness.

Depth Perception Errors — Reduced ambient light increases depth perception mistakes.

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.

Unstable Visual Ascents — Relying on wall visuals can destabilise ascents.

Gradual Depth Creep — Lack of visual bottom reference can cause unnoticed descent.

Unsignalled Downcurrents — Downcurrents can form without visible indicators.

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.