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.
How a band speargun works
Explainer · Last reviewed 2026-08-18
Stretched rubber stores energy and releases it into a shaft, and every design decision — band length, band diameter, shaft mass, gun length — is a way of trading how much energy is stored against how fast it can be delivered.
Safety
Knives and cutting tools — Can cause injury needing treatment
A band or wishbone failing under load during loading can strike the person loading it, and a loaded gun discharging outside the water can injure anybody in front of the muzzle.
What reduces it: Loading only in the water with the muzzle pointed away, replacing bands and wishbones on age as well as appearance, inspecting the notch and line release before each session, and unloading before leaving the water.
A band gun is a spring. Rubber bands are stretched over a notch in the shaft, held by a trigger mechanism, and released. The energy stored in the stretched rubber accelerates the shaft down a track and out of the muzzle.
The components are few. A stock or barrel, a muzzle, a handle with a trigger and a line release, a shaft, and one or more bands with a wishbone that engages the shaft.
WHAT DECIDES PERFORMANCE. Energy stored rises with band cross-section and with how far the band is stretched relative to its resting length. Energy delivered depends on how much of that goes into the shaft rather than into moving the rubber itself and into recoil — which is why a very heavy shaft accelerates less and a very light one wastes energy the rubber cannot transfer efficiently.
RECOIL IS THE PART PEOPLE MISS. Every unit of momentum given to the shaft is given equally to the gun in the opposite direction. A powerful gun kicks, and kick moves the muzzle before the shaft has left it. This is why a heavier gun of the same power is more accurate, and why adding bands to a light gun produces a weapon that is powerful and hard to aim.
MULTIPLE BANDS multiply power and multiply loading effort. Loading a heavily banded gun in the water, repeatedly, while breathing up, is a genuine physical cost and is a reason many experienced divers use less power than they could.
Loading, and the safety rules that come with it
Loading is when people get hurt, and the mechanism is always the same: a band under tension slipping, or a gun discharging while pointed at somebody.
The gun is loaded in the water, pointed away from everybody including yourself, with the butt braced against the hip or chest and both hands on the band. It is never loaded on a boat deck or a beach. A loaded gun is treated as capable of firing at any moment, because a worn wishbone or a damaged notch means it is.
The safety catch is a mechanical device that can fail and is not a substitute for muzzle discipline. The rule that actually works is that the muzzle never covers anything you are not willing to shoot.
Unloading is done deliberately — either by firing into open water or sand, or by carefully removing the band tension — and never by carrying a loaded gun out of the water. Most spearguns are unloaded before the diver exits, for the same reason a firearm is.
Authoritative guidance
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
- 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 handling powered equipment in and out of the water.Background and mechanism onlyCitation checked — the work exists and is described correctly
Failure modes and inspection
Band guns fail in a small number of predictable ways, and all of them are visible before they happen.
BANDS PERISH. Rubber degrades with UV, salt, ozone and time, and a band that has surface cracking or has gone hard is a band that will snap under load — sometimes in the face of the person loading it. Bands are consumable and are replaced on age as well as on appearance.
WISHBONES WEAR. The wishbone is the small loop that engages the shaft notch, and it takes the whole load. Dyneema wishbones abrade; metal ones fatigue. This is the component most likely to fail and the cheapest to replace.
THE SHAFT NOTCH ROUNDS OFF. A worn notch releases early, which is both a lost fish and a discharge nobody intended.
THE LINE RELEASE AND TRIGGER accumulate salt and grit and become unreliable.
Inspection before a session is a look at all four, and it takes under a minute. The maintenance page covers what salt does and how to prevent it.
Where to go next
Where it matters
- Boat divingA gun is loaded in the water and unloaded before coming aboard, which is a boat-deck rule rather than a diving one.
- Reef spearfishingReef work is where band guns dominate, because they are quiet and field-repairable.
- SpearfishingThe mechanism of the discipline's principal tool, including the stored energy that makes loading the dangerous moment.
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.
Boat diving
Where loaded-gun handling errors occur.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear classification and construction for spears and powered spear devices.States this directlyCitation checked — the work exists and is described correctly
Reef spearfishing
The technique where the mechanics matter most.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear classification and construction for spears and powered spear devices.States this directlyCitation checked — the work exists and is described correctly
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
Gear this affects
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.
Spearguns
An explainer carrying a mechanism the equipment record depends on.
- CMAS technical and sporting standards for underwater activities — Confédération Mondiale des Activités Subaquatiques (Standards body)Relied on for: Breath-hold spearfishing practice, equipment convention and the safety expectations set out by the international underwater federation.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: Spearfishing equipment and practice: gun, shaft, tip and rigging choice, and the handling of a shot fish, from a practitioner tradition distinct from the European one.States this directlyCitation checked — the work exists and is described correctly
How this compares
- Roller and inverted-roller speargunsThe roller is a refinement of the band gun rather than a different system, and the conventional arrangement remains the one with almost nothing to go wrong.
- Spearguns and slingsStored elastic energy, band stretch and shaft mass, and the recoil that follows from all three.
What these connections rest on (2)
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.
Roller and inverted-roller spearguns
Two records a reader is deciding between, joined so that the trade is visible from either side.
- BlueWater Hunting and Freediving — BlueWater Freedivers, Ventura, California, 1995 (Practitioner report)Relied on for: Spearfishing practice including equipment selection, rigging, technique and the reasoning behind gear choices.States this directlyCitation 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: International underwater federation standards for training, competition and the safe conduct of underwater activities.States this directlyCitation checked — the work exists and is described correctly
Authoritative guidance — 1 connection
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Spearguns and slings
The canonical record covers the family; this covers the mechanism.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear classification and construction for spears and powered spear devices.States this directlyCitation checked — the work exists and is described correctly
Sources for this page
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear classification and construction for spears and powered spear devices.Background and mechanism onlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.