Bands, wishbones and when to replace them
Explainer · Last reviewed 2026-08-18
The two components carrying the entire load of a band gun are also the two that degrade invisibly with age rather than with use — which is why they are replaced on a calendar as well as on inspection.
Safety: knives and cutting tools — can cause injury needing treatment.
Never dive alone, dive one up one down, and never extend a dive for a fish.
A band gun's power passes through rubber and through a small loop. Both are consumables, and both fail in ways that can injure the person loading the gun.
BANDS are latex rubber tubing. They degrade through UV exposure, ozone, salt, heat and simple age, and the degradation is chemical rather than mechanical — a band stored in a garage for two years has aged whether or not it has been used. Signs are surface cracking, a chalky or hardened feel, loss of elasticity, and any nick or cut at all.
A band that snaps under load releases a great deal of energy suddenly, usually while the diver is stretching it near their own face.
WISHBONES are the small loop — Dyneema cord or metal — that engages the shaft notch. They take the full band load at a single point. Dyneema abrades and can be inspected visually; metal wishbones fatigue and can fail without visible warning, which is why age matters for them too.
BAND LENGTH AND STRETCH RATIO are the tuning variables. A band is cut so that it stretches to a particular multiple of its resting length when loaded. Too little stretch and the gun is weak; too much and the band is being worked near its limit, which shortens its life and raises the risk of failure. Manufacturers specify this and it is one of the specifications worth respecting.
Storage is where most band life is lost
Bands degrade faster out of the water than in it, and the two worst places to keep a gun are a car and a sunny shed.
UV is the principal enemy. So is heat, and so is ozone — which is generated by some electric motors, making a garage with power tools a surprisingly poor storage location. Salt left on the rubber accelerates everything.
The practical routine is short: rinse in fresh water after every session, dry out of direct sunlight, store somewhere cool and dark, and store the gun unloaded so the bands are at rest rather than stretched.
A gun stored loaded has its bands under constant tension, which takes a set in the rubber and reduces both power and life. It is also, separately, a loaded weapon in a cupboard.
Replacing on age, and what that period is
There is no universal interval, and the honest reason is that band life depends on how a gun has been used and stored rather than on how long ago it was bought.
What can be said is that bands are the cheapest safety-relevant component in the system, that the cost of replacing them a season early is trivial, and that the cost of a failure is an injury. Divers who use their guns regularly commonly replace bands at least annually and inspect them before every session; a gun that has been stored for a long period gets new bands before it is used, whatever they look like.
Wishbones are replaced with the bands as a matter of course, because they are cheaper still and because a new band on a worn wishbone has simply moved the failure point.
What experienced anglers do — why, and the sources (2)
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.
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Diving equipment inspection and replacement practice for load-bearing consumable components.States this directlyCitation checked — the work exists and is described correctly
- AIDA International freediving education and safety standards — AIDA International (Water-safety or diver-training authority)Relied on for: Freediving equipment standards including inspection and replacement of load-bearing components before use.States this directlyCitation checked — the work exists and is described correctly
Safety
Never dive alone, dive one up one down, and never extend a dive for a fish. The full set of breath-hold essentials — training, the buddy system, conditions, equipment and visibility — is on the spearfishing safety page.
Knives and cutting tools — Can cause injury needing treatment
A perished band or worn wishbone snapping under load releases the stored energy suddenly, usually while the diver is stretching it close to their own face and hands.
What reduces it: Inspecting bands and wishbones before every session, replacing on age as well as appearance, storing the gun unloaded out of sunlight and heat, and rinsing salt off after every dive.
Where to go next
Where it matters
Related reading
How this compares
Sources and evidence
- FAO fishing gear types and fishing technology information — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Gear construction and material specification for elastic-powered spear devices.Background and mechanism onlyCitation checked — the work exists and is described correctly
Why the 4 connections on this page are here, and the sources
Where it matters
Official guidance — 1 connection
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 page 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
Official guidance — 1 connection
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Spearguns and slings
The failure mode that injures people.
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Equipment inspection and replacement practice for load-bearing consumable components.States this directlyCitation checked — the work exists and is described correctly
How this compares
Official guidance — 2 connections
Stated by a fisheries authority, scientific institute or recognised angling body. Authoritative, but summarising rather than demonstrating.
Bands and wishbones
The component record and the replacement discipline it needs.
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Equipment inspection and replacement practice for load-bearing consumable components.States this directlyCitation checked — the work exists and is described correctly
Salt, corrosion and what it does to tackle
Storage rather than diving is where most band life is lost.
- BSAC diving safety guidance and annual incident report — British Sub-Aqua Club (Water-safety or diver-training authority)Relied on for: Equipment inspection and replacement practice for load-bearing consumable components.States this directlyCitation checked — the work exists and is described correctly
How FishingHQ labels evidence is explained in the evidence policy.