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.
When to call a dive off
Explainer · Last reviewed 2026-08-17
The most valuable decision in the discipline and the least taught — and the reason it is hard is that every factor pushing towards getting in is immediate while every factor pushing against it is hypothetical.
Safety
Drowning and immersion — Can cause serious injury or death
Divers enter or continue in conditions they would decline if the decision were free, because the pressures to dive are immediate and the pressures against are hypothetical.
What reduces it: Agreeing abort conditions with a buddy on land before arriving, checking the exit on the way in, and treating going home as a normal outcome rather than as a failure.
Almost every spearfishing incident has a moment before it where somebody could have decided not to. The decision is rarely difficult on the evidence; it is difficult on the psychology.
The pressures to dive are concrete and present: the drive took two hours, the tide is right, the forecast might be worse tomorrow, the buddy has come a long way, the fish were here last week. The pressures against are abstract: it MIGHT get worse, the visibility is POSSIBLY too poor, you are PROBABLY tired enough to matter. Concrete beats abstract, reliably, which is why experienced divers get into water they should not.
THE ANSWER IS TO DECIDE BEFORE YOU ARRIVE. Agreeing the conditions that would end the session — with a buddy, on land, before anybody has invested anything — moves the decision to a moment when the pressures are balanced. 'We don't get in if the swell is above X or the viz is under Y' is a decision that survives having driven two hours; a judgement made at the water's edge is not.
WHAT SHOULD END IT. Deteriorating visibility. Rising swell or surge. A current stronger than a comfortable swim against. Cold that has stopped being uncomfortable and started being numbing. Fatigue. Illness or congestion. A buddy who is not right. Equipment that has failed. Any hypoxic event. And the unquantifiable one that experienced divers respect: a session that feels wrong.
Stopping is a normal outcome, not a failure
This section exists because the framing matters more than the criteria.
A diver who drives to the coast, looks at the water and drives home has had a successful session by every measure that matters. Nothing was lost except time, and the alternative — getting in to justify the journey — is the exact mechanism behind a substantial share of incidents.
The same applies mid-session. Getting out early because the swell has built, because you are colder than you expected, or because your buddy has had enough is the system working. There is always another day, and the phrase is a cliché because it is true and because the people it would have saved are not available to say it.
FishingHQ's standing principle across every discipline is that no fish is worth an injury. In spearfishing that principle has a sharper edge than anywhere else on this platform, because the margin between an ordinary dive and a fatal one is measured in seconds of consciousness.
The conditions that most often turn mid-session
SWELL AND SURGE build faster than they subside and are most dangerous at the exit rather than the entry. An entry that was easy an hour ago may not be an exit now, which is why the exit is checked on the way in.
WIND changes surface chop, which changes both the diver's visibility to boats and the buddy's ability to see the diver.
CURRENT often strengthens with the tide on a schedule that is knowable in advance and forgotten in the water. A diver who has drifted downcurrent while hunting has a swim back they did not plan.
VISIBILITY drops with swell stirring the bottom, with rain runoff and with plankton blooms. Falling visibility removes the buddy's ability to observe, which removes the safety system rather than merely the fishing.
And COLD arrives last and is noticed least. Shivering that has stopped is not a good sign.
Authoritative guidance
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water safety guidance on cold water, changing conditions and decision-making before entering the water.States this directlyPassage read and verified
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Diving safety guidance on conditions assessment, aborting dives and incident contributors.States this directlyCitation checked — the work exists and is described correctly
Where to go next
Where it matters
- SpearfishingAgreeing abort conditions on land moves the decision to a moment when the pressures are balanced.
- Boat divingHaving paid for a charter is the clearest example of a concrete pressure beating an abstract one.
- Shore divingAn entry that was easy an hour ago may not be an exit now, which is the decision shore divers most often get wrong.
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.
Spearfishing
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
A discipline-level practice rather than a technique.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water safety guidance on assessing conditions and on decision-making before entering the water.States this directlyPassage read and verified
Boat diving
The setting where sunk cost most distorts the judgement.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water safety guidance on assessing conditions and on decision-making before entering the water.States this directlyPassage read and verified
Shore diving
The discipline where the abort decision is hardest and most consequential.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water safety guidance on assessing conditions and on decision-making before entering the water.States this directlyPassage read and verified
Related reading
- Cold water, and how quickly it degrades judgementThe response to cold is always the same and it is the whole answer: get out, while you are still the person able to decide that.
- Planning a dive sessionThe threshold for not getting in has to be set before standing at the water's edge, where everything argues for getting in.
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.
Cold water, and how quickly it degrades judgement
Where the cold sequence ends, and the record that treats stopping as a normal outcome.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water-safety guidance on cold immersion, surface visibility and informing somebody ashore.States this directlyPassage read and verified
Planning a dive session
The decision this record exists to move earlier in the day.
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Diving safety guidance on planning, conditions assessment, buddy protocol, entanglement and equipment handling.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.
Reading underwater conditions
The conditions record supplies what the decision is made about.
- RNLI water safety guidance: cold water shock and Float to Live — Royal National Lifeboat Institution (Water-safety or diver-training authority)Relied on for: Water safety guidance on assessing conditions and on decision-making before entering the water.States this directlyPassage read and verified
Sources for this page
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Diving safety guidance and annual incident analysis.States this directlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.