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.

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.

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.