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.
Flashers, and what attracting a fish actually changes
Explainer · Last reviewed 2026-08-17
A hung array of reflective blades used in blue water to bring curious pelagic fish to a diver who cannot go and find them — and a technique that changes the encounter, the shot and the risk picture all at once.
Safety
Entanglement — Can cause serious injury or death
A flasher adds a hanging line and hardware to water that already contains a shooting line, a breakaway line and one or more float lines, all drifting at slightly different rates around a stationary diver whose attention is on an approaching fish. Entanglement on a breath-hold is a time-limited emergency with no option to stop and think.
What reduces it: Carry a cutting tool reachable with either hand and locatable without looking. Keep every line as short and as tidy as the job allows. Use breakaway rigging so a running fish is transferred to floats rather than to you. Dive with a buddy positioned to reach you, and with a competent person on the boat watching the floats.
Worse when:
- In current, which moves the flasher, the floats, the divers and the boat at different rates
- After a shot, when a fish is running through the same volume of water as the rig
- With several divers working one flasher
Shallow water blackout and breath-hold loss of consciousness — Can cause serious injury or death
Flasher work concentrates the encounter into a short window, and the temptation to hold on for a circling fish arrives at the end of a breath-hold in open water with no bottom to rest on. Blackout gives no warning and an unconscious diver in blue water is not found by accident.
What reduces it: Set the dive time on the surface and surface on it whether or not a fish is circling. One up, one down, with the surface diver watching the ascent and the first thirty seconds after it. Never hyperventilate.
Boat traffic and being seen — Can cause serious injury or death
Divers, floats and a flasher spread across open water are difficult to see from a vessel, and offshore traffic is fast. A diver separated from the group and from the floats is close to invisible.
What reduces it: Marked floats kept close, a competent person aboard whose job is watching, and an agreed arrangement for re-forming the group as everything drifts.
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.
- Carry a charged phone in a waterproof case, or another means of calling for help.
- Tell somebody where you are going and when you expect to be back.
A flasher is a line hung from a float with a series of reflective metal blades on it, deployed in open water and left to turn and glint with the swell. Pelagic fish investigating the flash come to it, and the diver waits nearby.
WHAT IT IS ACTUALLY DOING. Blue water contains no structure, no landmark and frequently no fish. A diver cannot cover enough of it to find travelling pelagic species by searching, and cannot approach them by swimming when they are found. A flasher inverts the problem: instead of the diver finding the fish, a point of interest is created in featureless water and the fish come to inspect it. It works on curiosity rather than on hunger, which is why it is not bait and is not regulated as bait in most places that regulate bait at all.
IT IS ALSO A DEPTH REFERENCE, AND THAT IS NOT INCIDENTAL. In open water with no bottom in sight, a hanging line with visible markers on it is one of the few things telling a diver which way is up, how deep they are and how far they have drifted. Blue-water divers describe that as a safety function of the rig rather than a bonus.
WHAT IT CHANGES ABOUT THE ENCOUNTER. Fish arrive from below and behind more often than in front. They arrive fast, they circle, and the useful window is short. The diver is stationary, near a line, in open water, with a loaded gun and a float line in the water — which is a specific arrangement of hazards and is the reason this technique belongs to divers who already have the discipline rather than to divers acquiring it.
AND IT IS NOT A REEF TECHNIQUE. On structure there is already a reason for fish to be somewhere, and a flasher adds line to the water for no gain. This is a blue-water tool, used from a boat, in the branch of the sport with the least margin for error.
More line in the water, in the place where line is most dangerous
Every honest description of flasher work has to start with the arithmetic of what is now floating around the diver, because the technique's cost is entanglement and the cost is paid in the environment least forgiving of it.
COUNT THE LINES. A blue-water diver already has a shooting line, a breakaway line, a float line and one or more floats. A flasher adds a hanging line with hardware on it, held by its own float, drifting on its own with a current that is moving everything at slightly different rates. The diver then hovers in the middle of that arrangement, watching downward and behind, at the point in a breath-hold when attention is narrowest.
ENTANGLEMENT ON A BREATH-HOLD IS A TIME-LIMITED EMERGENCY, which is the sentence that separates this from a tangle on a boat. There is no option to stop and sort it out, no option to breathe while thinking, and the time available is whatever is left of the breath — reduced, because the diver is now working. That is why a cutting tool reachable with either hand, without looking, is not equipment in this discipline but part of the safety system.
THE SHOT MAKES IT WORSE RATHER THAN BETTER. A fish taken beside a flasher is a fish running through a volume of water containing several other lines. This is the specific case breakaway rigging exists for — the shooting line separates from the gun so the fish is transferred to floats rather than to the diver — and it is the case where a fixed line to a large pelagic fish is a person being towed through their own rigging.
AND THE BOAT IS PART OF THE SYSTEM, NOT A CONVENIENCE. Blue-water work happens with a competent person aboard, watching, able to reach a diver and able to see the floats. A drifting flasher, drifting divers and a drifting boat separate at different rates, and re-establishing that arrangement is the boat's job rather than the divers'.
WHAT FISHINGHQ WILL NOT PUBLISH is a rigging recipe for this. The arrangement depends on the current, the vessel, the depth, the quarry and the number of divers, and it is set up by people who have been shown how — which is the same answer this catalogue gives about every other part of the blue-water picture, for the same reason.
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: Freediving safety practice: hypoxic blackout and its absence of warning symptoms, surface supervision, and the management of equipment failure and entanglement on a breath-hold.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 covering buddy protocol, entanglement, equipment failure in the water and the incident patterns behind both.States this directlyCitation checked — the work exists and is described correctly
- BlueWater Hunting and Freediving — BlueWater Freedivers, Ventura, California, 1995 (Practitioner report)Relied on for: Established practitioner description of spearfishing technique, rigging configuration and the handling of a shot fish, recorded as practitioner literature rather than as scholarship.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
Where to go next
Where it matters
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.
Blue-water 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.
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold spearfishing as a defined discipline with its own technical, equipment and safety standards, set out by the international underwater federation.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 the safety requirements of breath-hold diving apply across the discipline rather than to particular equipment or techniques within it.States this directlyPassage read and verified
Related reading
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.
Reels, float lines and breakaway systems
One record resolves a question the other raises and cannot answer alone.
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold spearfishing as a defined discipline with its own technical, equipment and safety standards, set out by the international underwater federation.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 the safety requirements of breath-hold diving apply across the discipline rather than to particular equipment or techniques within it.States this directlyPassage read and verified
Safety reading
- Entanglement while breath-hold divingThe technique's whole cost is more line in the water, in the environment least forgiving of it.
- Surface markers and boat trafficDivers, floats, flasher and boat spread across open water and drift apart at different rates.
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.
Entanglement while breath-hold diving
A safety topic that applies to this record specifically rather than to the discipline generally.
- 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
Surface markers and boat traffic
A safety topic that applies to this record specifically rather than to the discipline generally.
- 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
Rules and access
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.
Method and bait restrictions
A link to a rule CONCEPT rather than to a rule. The record already renders the regulatory-variance notice by its own declaration; this edge says WHICH rules bear on it, which turns a generic warning into a route to the body that holds the current answer.
- Environment Agency fisheries management, byelaws and rod licensing information — Environment Agency (Government fisheries body)Relied on for: Freshwater and transitional-water fisheries management, the structure of licensing, close seasons and byelaws, and the measures applied to gear, bait, retention and fish movement.States this directlyCitation checked — the work exists and is described correctly
- Angling Trust guidance for anglers — Angling Trust (Angling or fisheries organisation)Relied on for: Guidance to anglers on fishery rules and conditions of access, including the restrictions individual waters and authorities set.States this directlyCitation checked — the work exists and is described correctly
Check the rules before you fish
Fishing laws, bylaws, access rules, seasons, bait restrictions and permitted methods vary by location and can change. Check the current rules from the relevant authority and the water you intend to fish before fishing.
Check with:
- Current national or regional law for where you are fishing
- Current local bylaws
- The relevant fisheries authority
- The landowner, club or fishery whose water it is
- Any restrictions specific to the species or the method you intend to use
Sources for this page
- BlueWater Hunting and Freediving — BlueWater Freedivers, Ventura, California, 1995 (Practitioner report)Relied on for: Established practitioner description of spearfishing technique, rigging configuration and the handling of a shot fish, recorded as practitioner literature rather than as scholarship.FishingHQ's interpretation of what it saysCitation checked — the work exists and is described correctly
- 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, equipment practice and the safety expectations set by the international underwater federation.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 and its absence of warning symptoms, surface supervision, and the management of equipment failure and entanglement on a breath-hold.States this directlyPassage read and verified
How FishingHQ labels evidence is explained in the evidence policy.