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.

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.

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.