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.
Speargun length, and what it decides
Explainer · Last reviewed 2026-08-18
Length trades reach and accuracy against manoeuvrability, and the water decides which matters — a hole hunter and a blue-water diver need opposite answers, which is why there is no beginner's number.
Safety
Line under tension — Can cause injury needing treatment
A longer gun stores more energy and carries more line, and both are released at once on a shot. In confined ground — a gully, a kelp stand, a hole — a long gun is also difficult to swing and to unload safely, and the loading stroke that a long band demands is where most speargun injuries happen.
What reduces it: Match gun length to the ground rather than to reach, keep the muzzle pointed away from everybody including yourself throughout loading and unloading, and unload in the water deliberately before passing the gun to anybody or bringing it aboard.
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.
Gun length is the first specification anybody meets and the one most often answered with a number that cannot be right for everybody.
WHAT LENGTH BUYS. A longer gun accommodates longer bands, so it stores more energy and shoots further and flatter. It also has a longer sight line between the muzzle and the eye, which makes aiming more precise in the same way a longer barrel does on any aimed weapon. And a longer shaft carries more momentum, so it penetrates better.
WHAT LENGTH COSTS. Manoeuvrability, in three ways. A long gun is slow to swing onto a moving fish. It cannot be brought to bear in a hole, a gully or a kelp stand. And it is physically tiring to swim with, particularly in current.
WHICH DOMINATES IS DECIDED BY VISIBILITY AND BY QUARRY. In clear blue water where fish are seen at distance and the shot is long, reach is everything. In three metres of British visibility a long gun is a liability, because the shot is close and the fish appears and disappears in a second.
So the honest guidance is a mapping rather than a number: short guns for confined ground, poor visibility and close work; mid-length for general reef and rock diving; long guns for open water, large fish and long shots.
Why a beginner is usually better served short
Two reasons, and neither is about capability.
The first is that a beginner's shots are close. Approaching fish is the skill that takes longest to acquire, and until it is acquired the fish that are shot are the ones that came close anyway. A long gun adds reach that is not being used and subtracts handling that is.
The second is safety and control. A shorter gun is easier to keep under positive control while loading, while swimming through structure and while surfacing — and control is what stops a gun becoming a hazard to a buddy.
The pattern most training suggests is starting short and adding length as the diving demands it, rather than buying for the diving somebody hopes to do.
That also has a practical benefit: a short gun bought first remains useful forever, because confined ground and poor visibility never stop existing. A long gun bought first spends its first season being the wrong tool.
Length conventions differ, and so does what they mean
Guns are quoted by length in centimetres in most of the world and occasionally in inches. The number usually refers to the barrel or stock rather than the overall length including the shaft overhang, and manufacturers do not measure it identically — so two guns quoted at 90 cm are not necessarily the same size.
More usefully, the same number means different things in different traditions. A 110 cm gun is a general-purpose reef gun in the Mediterranean and a short gun in Australian blue-water terms.
The transferable approach is to think in terms of what the gun must do — reach a fish at the distance your visibility allows, and swing where your ground allows — rather than in a number somebody quoted for a different coast.
Where to go next
Where it matters
- Hole huntingA long gun cannot be brought to bear in a hole, a gully or a kelp stand.
- SpearfishingGun length is a spearfishing equipment decision with loading, handling and ground consequences.
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.
Hole hunting
The clearest case where length is the wrong variable to maximise.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Spear and powered spear gear specification and classification.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
- Reading underwater conditionsIn three metres of visibility a long gun is a liability, because the shot is close and brief.
- Spearguns and slingsLength trades reach and accuracy against manoeuvrability, and visibility decides which matters.
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.
Reading underwater conditions
Conditions decide the answer more than preference does.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Spear and powered spear gear specification and classification.States this directlyCitation checked — the work exists and is described correctly
Spearguns and slings
The specification a reader meets first and the one most often answered with a wrong number.
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Spear and powered spear gear specification and classification.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: Spear and powered spear gear specification and classification.Background and mechanism onlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.