For the majority of divers, a shark encounter is the highlight of the dive. The grey reef sharks finning past a seamount, the occasional white tip resting under a coral ledge, the silhouette of something larger emerging from the blue — these are moments that remind you why you got into the water in the first place.
The small number of encounters that escalate beyond the ordinary share common characteristics, and most of them were avoidable. Here is what the science and field experience say about managing shark encounters underwater.
Why Divers Are Generally at Lower Risk
Scuba divers experience far fewer shark bite incidents per hour in the water than surfers or swimmers, and the reasons are well understood. A diver underwater is a large, neutrally buoyant object exhaling a continuous stream of bubbles — a sensory profile unlike any natural prey item. They move slowly and deliberately. They can maintain eye contact with any shark in their vicinity.
Eye contact itself is relevant. Prey animals do not face predators. A diver who turns to face an approaching shark and holds that position is communicating, in the body language the ocean understands, that it is not fleeing prey.
Reading Shark Body Language
Most sharks encountered on a dive are in one of several recognisable states:
- Passing through: the shark is moving with purpose and shows little interest in you. It may glance, adjust its path slightly, and continue. This is normal and requires nothing from you except to watch it.
- Investigating: the shark has noticed you and is making closer or more deliberate passes. It is assessing. This is still normal behaviour and most investigatory passes resolve to departure without incident. Face the animal, stay calm, avoid erratic movements.
- Agonistic display: the shark has moved into a state of active threat communication. Signs include a stiff-bodied, exaggerated swimming motion, back arching, pectoral fins dropping below horizontal, and pronounced head movement. This is well documented in grey reef sharks and has been observed in other reef species. It is the shark's warning system — it is telling you to increase distance. Do so, slowly, facing the animal.
The critical skill is not reacting to any shark encounter as if it were an emergency, but accurately reading which category the behaviour falls into and responding proportionally.
Practical Guidelines for Scuba Divers
- Stay close to structure when you can. Being against a wall or reef limits the angles from which a shark can approach and reduces the vulnerability that comes with open-water drifting in areas of known shark activity.
- Do not approach sharks to get closer. Particularly with species like grey reef sharks that are territorial around reef environments, pushing in on an animal that is showing any sign of displeasure is the most reliably effective way to escalate an encounter.
- Avoid diving at dawn and dusk where sharks are known to be present and actively hunting. The crepuscular windows that elevate risk for surfers apply equally underwater.
- Ascend in a controlled, unhurried manner and maintain awareness of what is above you. This is particularly relevant for freedivers — a vertical ascent in low-visibility conditions or areas of pelagic shark activity introduces a silhouette and movement pattern that warrants attention.
- Exit the water calmly if a shark is showing sustained interest or agonistic behaviour. Ascending with your eyes on the shark, maintaining eye contact throughout the ascent, is both practical and consistent with what field evidence suggests about deterring further approach.
For Freedivers Specifically
Freediving removes the bubble stream and mechanical noise signature of scuba equipment, which changes the interaction profile. Most freedivers report that marine life, including sharks, seems relatively indifferent to their presence — which aligns with what you would expect from an animal with sophisticated sensory systems encountering a slow, quiet, non-threatening object.
The one specific risk scenario worth naming is the surface interval. A freediver floating face-down at the surface during a breath-hold recovery presents a profile — horizontal, at the surface, intermittently still — that has some similarity to a distressed or resting marine mammal when viewed from below, particularly in low-visibility conditions. Staying active during recovery intervals, or floating vertically rather than horizontally, reduces this profile.
What to Carry
A freediving or scuba emergency can happen far from shore and far from other divers. For any dive in environments where large sharks are known to be present, carrying a personal shark deterrent device and diving in a bite-resistant wetsuit represents the same kind of layered precaution that experienced divers apply to every other aspect of their kit selection.
The goal is to enjoy every dive. Preparation is what makes that possible.
Shark Stop's bite-resistant wetsuits are worn by scuba divers and freedivers across Australia and internationally. Protection that moves with you in the water means less distraction and more dive. See the range here.