Training and courses
Safety · Last reviewed 2026-08-10
The one piece of spearfishing equipment that cannot be bought secondhand — and the only intervention that reliably changes what happens when something goes wrong.
Safety
Shallow water blackout and breath-hold loss of consciousness — Can cause serious injury or death
Hypoxic blackout causes loss of consciousness without warning, most often during ascent or at the surface. An unconscious diver who is not brought to the surface and whose airway is not held clear will drown within minutes.
What reduces it: Formal training before you spearfish, not after. One up, one down with a named buddy who has been trained in rescue and is positioned to reach you. Never hyperventilate. Surface intervals longer than the dive. Weight yourself to float at the surface so an unconscious diver rises rather than sinks.
Worse when:
- After hyperventilation, which removes the warning without adding oxygen
- On repeat dives with short surface intervals
- When cold, tired, or extending a dive for a fish
Precautions that always apply here
- Never spearfish or freedive alone.
- Dive one up, one down: one diver down, one on the surface actively watching, every single dive.
- Never hyperventilate before a breath-hold. It delays the urge to breathe without adding oxygen, which is precisely the mechanism behind shallow water blackout.
- Tell somebody where you are going and when you expect to be back.
- Carry a charged phone in a waterproof case, or another means of calling for help.
Spearfishing is the only branch of fishing where the participant can die from doing the thing correctly rather than from an accident. That single fact is why training sits at the top of this section rather than in it.
A freediving course teaches four things that cannot be worked out alone. It teaches equalisation properly, which is the difference between diving comfortably and damaging your ears. It teaches breathing and relaxation, and — critically — teaches why hyperventilation is dangerous rather than helpful, which is the opposite of what most people intuit. It teaches buddy procedure: not the slogan, but where to be, what to watch for, and what an ascending diver looks like just before they black out. And it teaches rescue: how to bring an unconscious diver to the surface, how to hold an airway clear, and how to perform blow-tap-talk, which is the intervention that actually recovers people.
That last item is the argument in a sentence. Almost everybody who survives a shallow-water blackout survives it because somebody who was watching them knew what to do in the following seconds. Nobody works that out on the day.
Courses are run by several international bodies to broadly comparable syllabuses. The specific badge matters far less than that somebody assessed you doing the rescue in the water.
What a course covers that a diver will not discover alone
EQUALISATION. There is more than one technique, they suit different people and different depths, and the wrong one produces pain, failed dives and eventually injury. This is taught in an afternoon and takes years to arrive at by trial.
WHY HYPERVENTILATION IS DANGEROUS. This is the single most counter-intuitive item in the sport. Breathing hard before a dive feels like preparation and produces a longer, more comfortable breath-hold — because it lowers carbon dioxide, which is what drives the urge to breathe. It does not meaningfully increase the oxygen carried. The result is that the warning arrives later while the danger arrives at the same time, which is precisely the wrong trade. Nobody deduces this from experience, because the experience is that it works right up until it does not.
BUDDY PROCEDURE. Not "dive with a friend" but where to position, when to descend to meet an ascending diver, what to watch on the last few metres, and how long to stay with somebody after they surface. Most blackouts happen at or just below the surface, on the ascent, in the last part of a dive that was going fine.
RESCUE. Bringing an unconscious diver up, removing their mask, holding the airway clear of the water, and blow-tap-talk. This is a physical skill with a sequence, practised in the water on a person who is pretending to be unconscious. Reading about it is not the same activity.
And RECOGNITION — the samba, or loss of motor control, which frequently precedes or accompanies blackout and which an untrained observer reads as the diver being fine and slightly odd.
Authoritative guidance
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Hypoxic blackout physiology, the role of carbon dioxide in the urge to breathe, why hyperventilation increases risk, and that blackout frequently occurs during ascent or at the surface.States this directlyPassage read and verified
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That structured, assessed freediving training exists internationally, covering equalisation, breathing, buddy procedure and rescue.States this directlyCitation checked — the work exists and is described correctly
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Buddy protocol and rescue practice as standard components of diver training.States this directlyCitation checked — the work exists and is described correctly
Where to go next
Fishing this applies to
- Freediving for spearfishingFormal training is the prerequisite rather than the refinement, and the rescue component is the part that actually recovers people.
- SpearfishingThe only equipment that cannot be bought secondhand. Almost everybody who survives a shallow-water blackout survives because somebody trained was watching — nobody works that out on the day.
What these connections rest on (2)
Authoritative guidance — 2 connections
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Freediving for spearfishing
The same claim from the freediving side, where it is the entry condition.
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That structured, assessed freediving training exists and what it covers.States this directlyCitation checked — the work exists and is described correctly
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: That trained buddy rescue is what determines the outcome of a blackout.States this directlyPassage read and verified
Spearfishing
A safety claim about the single most effective intervention available, sourced to diving medicine and to a training body.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Hypoxic blackout physiology, the role of carbon dioxide in the urge to breathe, why hyperventilation increases risk, and that blackout frequently occurs during ascent or at the surface.States this directlyPassage read and verified
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That structured, assessed freediving training exists internationally, covering equalisation, breathing, buddy procedure and rescue.States this directlyCitation checked — the work exists and is described correctly
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Buddy protocol and rescue practice as standard components of diver training.States this directlyCitation checked — the work exists and is described correctly
Related reading
- Breath-hold physiology for spearfishersTraining works because it teaches the physiology that produces the risk.
- Fitness to dive: health, medication and when not toRecognised training organisations require a health declaration, which is where most people meet this question for the first time.
- Rescue principles for a blacked-out diverIn-water rescue is taught and assessed on recognised courses, and a buddy who has not done one is not what the safety model assumes.
- Speargun or pole spear to start withA pole spear defers a class of hazard — stored energy, loading, unloading and handling a loaded device — that a beginner can leave until after they have learned to dive. That is an argument about sequence rather than about danger.
What these connections rest on (4)
Authoritative guidance — 4 connections
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Breath-hold physiology for spearfishers
Training works because it teaches the physiology that produces the risk.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Diver safety guidance underlying this connection. Training works because it teaches the physiology that produces the risk.States this directlyPassage read and verified
Fitness to dive: health, medication and when not to
Where the assessment normally happens, and the reason to have it before a course.
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That recognised freediving education is structured and assessed, and includes in-water rescue.States this directlyCitation checked — the work exists and is described correctly
Rescue principles for a blacked-out diver
The intervention this record ends by recommending, and the only one that reliably changes the outcome.
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That recognised freediving education is structured and assessed, and includes in-water rescue.States this directlyCitation checked — the work exists and is described correctly
Speargun or pole spear to start with
A claim that a piece of equipment participates in a hazard substantial enough to have its own record, so that a reader meeting the component is routed to the full treatment rather than to a warning sentence.
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Technical and sporting standards for underwater activities, including spearfishing equipment practice, the conduct of the activity and its safety requirements.States this directlyCitation checked — the work exists and is described correctly
How this compares
What these connections rest on (1)
Authoritative guidance — 1 connection
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
How to start spearfishing
The training requirement stated as a first step.
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: Freediving education standards covering equalisation, weighting, buddy procedure and rescue skills.States this directlyCitation checked — the work exists and is described correctly
Sources for this page
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Hypoxic blackout physiology and the practices that reduce its incidence and consequence.States this directlyPassage read and verified
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That structured, assessed freediving training is available and what it covers.States this directlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.