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.

Deceptive Entry Openings — Openings may become restrictive inside due to angle, collapse, or corrosion.

Surge-Induced Internal Silt Shift — Internal surge can move silt and debris without direct contact.

Partial Overhead Environment — Many wrecks limit direct ascent even without full penetration.

Fine Rust Particle Silt-Out — Disturbed rust particles can rapidly reduce visibility.

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.

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.