Before you spearfish — this comes first

Get proper instruction before you spearfish. A recognised freediving or spearfishing course teaches the things that actually kill people in this sport, and reading about them is not the same as being taught them.
Dive with a buddy, and dive one up, one down — one diver in the water, one on the surface watching them, every dive. A breath-hold blackout is silent and gives no warning; a watching buddy is the difference between an incident and a fatality.
Stay inside your own training and experience. Depth and breath-hold times are personal, they change day to day, and nobody else's numbers apply to you.
Understand the conditions before you enter the water: visibility, current, swell, tide, boat traffic and your exit. Conditions decide whether a dive is reasonable far more often than skill does.
Use equipment you have been shown how to use, check it before every session, and be visible — a marked float and line are how boat traffic knows you are there.
Never extend a dive for a fish. No catch is worth pushing a breath-hold, and the urge to take one more second is exactly what a blackout feels like from the inside — which is to say, like nothing at all.

Freediving for spearfishing

Discipline · Last reviewed 2026-08-10

The breath-hold discipline underneath spearfishing — the part that has to be learnt properly, and the part that decides whether the rest is safe.

Safety

Shallow water blackout and breath-hold loss of consciousness — Can cause serious injury or death

Loss of consciousness from hypoxia, arriving without warning, most often during or just after ascent. An unconscious diver underwater with nobody watching does not recover.

What reduces it: Formal training with in-water supervision before diving unsupervised; one up, one down on every dive; no hyperventilation; surface intervals substantially longer than the dive; and an absolute rule that a fish is never a reason to stay down.

Barotrauma and pressure injury — Can cause injury needing treatment

Failing to equalise the ears and sinuses against increasing pressure on descent causes pain and can rupture an eardrum; forcing a descent through pain is how that happens. Mask squeeze produces facial and eye injury from a mask that has not been equalised.

What reduces it: Equalise early and often, starting before you feel the need. If equalisation fails, stop and ascend — a dive that will not equalise is a dive that does not happen. Exhale a little into the mask on descent. Never dive with a blocked nose or a cold.

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.

Spearfishing is a hunting technique layered on top of a diving discipline, and it is the diving discipline that carries the risk. A spearfisher who cannot manage a breath-hold safely is not a slower spearfisher; they are a person who will eventually black out underwater.

This record exists separately from spearfishing itself because the two are frequently conflated, and conflating them is how people arrive at the sport thinking of the diving as a means of getting to the fish rather than as the thing that requires training. It is the other way round: the hunting is the easy part.

What follows describes what the discipline consists of and what proper training covers. It does not teach breath-hold technique, and deliberately so — breath-hold training without direct supervision is the specific activity that kills people, and a web page cannot supervise anybody.

Section: Spearfishing
Coverage: Explained for context and understanding, not taught

FishingHQ covers this method for what it is, how it works, where it came from and what it costs the environment. It does not teach it. Some of these methods are restricted or prohibited in most jurisdictions, and for the commercial ones the useful content is the mechanism and the impact rather than instruction.

What it is

Diving on a single breath, without underwater breathing apparatus, as the basis of recreational spearfishing. It covers surface breathing preparation, equalisation of the ears and sinuses on descent, relaxed movement to conserve oxygen, controlled ascent, and structured surface recovery between dives.

How it works

A safe breath-hold cycle is mostly about what happens on the surface. Calm, unforced breathing before a dive; a relaxed descent that avoids working hard against buoyancy; equalisation carried out early and often on the way down; a controlled ascent with nothing left in reserve spent; and a surface interval substantially longer than the dive, during which a buddy watches. Each element is trainable and each is taught with direct supervision, in a controlled environment, before it is taken to the sea.

Equipment

A low-volume mask, a simple snorkel, long fins, an exposure suit appropriate to the water, and a weight belt with a quick-release buckle — weighted so the diver is positively buoyant at the surface and, critically, not so heavily that an unconscious diver would sink. A marked float and line complete the minimum.

Where there is disagreement

There is no meaningful controversy about the safety practices themselves; the diving authorities agree. Where practice diverges from guidance is in behaviour: solo diving, short surface intervals and pushing depth for a fish are all common and all specifically identified as dangerous. FishingHQ states the guidance rather than describing what people do.

What a course actually teaches, and why that list is the argument

'Get trained' is the most repeated sentence in this section and the least informative, because a reader who has not done a course does not know what they would be getting. Setting out the content is more persuasive than repeating the instruction, and it is the honest way to make the case.

A RECOGNISED FREEDIVING OR SPEARFISHING COURSE COVERS, in some order: what happens physiologically during a breath-hold and why the urge to breathe is not a measure of oxygen; what a hypoxic blackout is, why it gives no warning, and why the ascent is where it happens; loss of motor control and what it looks like from the surface; how to rescue an unconscious diver from depth and at the surface, practised repeatedly on a real person; how to be the buddy who is watching, which is a taught skill and not simply presence; equalisation and the injuries that follow forcing it; weighting for the individual, checked in the water by an instructor; and how to plan and abort a dive.

THE PART THAT CANNOT BE READ IS THE RESCUE. Recovering a diver who has blacked out is a physical sequence performed under time pressure on a person who is not helping, and it is learnt by doing it, wrongly, several times, with somebody correcting you. Reading the sequence produces a person who believes they could do it.

THE SECOND PART THAT CANNOT BE READ IS THE WEIGHTING. Correct weighting depends on suit thickness and age, body composition, the depth being dived and the dive plan, and getting it wrong in the heavy direction removes the buoyancy that keeps an unconscious diver at the surface. FishingHQ refuses to publish a weighting formula for exactly this reason and names the refusal in its tool ledger — a number produced by a web form would be applied by somebody who has no way to check it.

AND THE THIRD IS THE BUDDY SKILL. Watching a diver properly means knowing where to be, what to look for on the ascent, how long to keep watching after they surface, and what the first signs of trouble are — and it means being willing to intervene early and be wrong. Untrained buddies watch the fish.

WHAT THIS RECORD WILL NOT DO, and the refusal is the point: it will not teach breath-hold technique, publish progression tables, describe methods of extending a hold, or treat depth or time as a target. Breath-hold training without direct supervision is the specific activity that kills people, and there is no version of it that a page can supervise.

Authoritative guidance

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That structured, assessed freediving training exists, what it covers, and that breath-hold training requires direct supervision.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: Freediving safety practice: hypoxic blackout, its absence of warning symptoms, the ascent as the highest-risk phase, and the surface supervision that addresses it.States this directlyPassage read and verified
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 conduct, technique convention and the safety expectations set by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly

Where to go next

Techniques within this

Freediving for lobsterPractised by the same people, in the same water, with much of the same equipment and none of the same tackle — and until Sprint 28 the spearfishing vertical held 112 opportunities and said nothing about it.

What these connections rest on (1)

Practitioner consensus — 1 connection

Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.

Freediving for lobster
Placing a breath-hold hunting method inside the discipline that trains for it.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated practice connecting this quarry to this method.Background and mechanism onlyCitation checked — the work exists and is described correctly
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear classification and operating principle for the method described.States this directlyCitation checked — the work exists and is described correctly

Where it is practised

What these connections rest on (2)

Practitioner consensus — 2 connections

Strangford Lough and the Ards coast
A claim about angling convention rather than about the world: that this place sits within this branch of fishing, which drives the information architecture as well as the page. It rests on independent practitioner description.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated descriptions of which practices are conventionally used in the waters named, recorded as practitioner consensus rather than as scholarship.Background and mechanism onlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of British and Irish sea angling practice by region and by ground type.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
The Croatian Adriatic
A claim about angling convention rather than about the world: that this place sits within this branch of fishing, which drives the information architecture as well as the page. It rests on independent practitioner description.
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: Widely restated descriptions of which practices are conventionally used in the waters named, recorded as practitioner consensus rather than as scholarship.Background and mechanism onlyCitation checked — the work exists and is described correctly
- Sea Angler — Bauer Media (Specialist angling publication)Relied on for: Long-running published description of European sea angling practice by region and by ground type.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly

Skills and knowledge

2 more

Wetsuits, fins and masks for spearfishing Explainer
Why hyperventilation before a dive is dangerous Explainer

What these connections rest on (10)

Authoritative guidance — 10 connections

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

Breath-hold physiology for spearfishers
The physiology is the reason freediving is taught before it is practised.
- 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. The physiology is the reason freediving is taught before it is practised.States this directlyPassage read and verified
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Equalisation and pressure
Equalisation is a taught skill with real injury consequences.
- 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. Equalisation is a taught skill with real injury consequences.States this directlyPassage read and verified
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Equalisation, and the injuries that follow forcing it
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Loss of motor control, and what it is warning of
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Rescue principles for a blacked-out diver
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Shallow-water blackout: what it is, and why it gives no warning
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly
Using a kayak as a dive platform
The explanation behind a practice, joined to the surface a reader arrives at so that the reasoning is reachable rather than orphaned.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving safety, the mechanism of hypoxic blackout, and the requirement for direct supervision by a competent buddy on every dive.States this directlyPassage read and verified
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: Recognised freediving education and safety standards, including buddy procedure and the one-up-one-down principle.States this directlyCitation checked — the work exists and is described correctly
Weighting and buoyancy in spearfishing
Weighting is established in the water under instruction.
- 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. Weighting is established in the water under instruction.States this directlyPassage read and verified
Wetsuits, fins and masks for spearfishing
Freediving equipment differs from scuba equipment by design.
- 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. Freediving equipment differs from scuba equipment by design.States this directlyPassage read and verified
Why hyperventilation before a dive is dangerous
A membership assertion rather than a topical one: this record teaches the discipline or its equipment, so the discipline's mandatory safety posture applies to it.
- DAN guidance on freediving safety, hypoxia and shallow-water blackout — Divers Alert Network (Water-safety or diver-training authority)Relied on for: Freediving and breath-hold spearfishing safety practice, including the supervision requirement that applies across the discipline rather than to particular equipment.States this directlyPassage read and verified
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold diving safety practice and discipline definition set out by the international underwater federation.States this directlyCitation checked — the work exists and is described correctly

Compared with

SpearfishingThe diving discipline underneath the hunting one — and the part that actually requires training.

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.

Spearfishing
Recognised training standards treat breath-hold diving as a discipline in its own right.
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: That freediving is delivered as a structured, assessed discipline independent of any hunting application.States this directlyCitation checked — the work exists and is described correctly

Safety reading

What these connections rest on (3)

Authoritative guidance — 3 connections

Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.

The spearfishing buddy system
Breath-hold diving is where the buddy requirement originates.
- 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. Breath-hold diving is where the buddy requirement originates.States this directlyPassage read and verified
Training and courses
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
Breath-hold blackout
The same hazard, applied to the underlying diving discipline.
- 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 role of hyperventilation and ascent.States this directlyPassage read and verified

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, its lack of warning signs, and the risk added by hyperventilation.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 breath-hold training is delivered as an assessed, directly supervised discipline.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 equalisation guidance for breath-hold diving.States this directlyCitation checked — the work exists and is described correctly

How FishingHQ labels evidence is explained in the evidence policy.

Share this page