Spearfishing Float Guide

A float is the least exciting thing you'll buy and the piece most likely to matter on a bad day. It's what stops a boat running you over, what gets your gun back when you drop it, and what a decent fish drags around instead of dragging you.

It's also the piece beginners rig wrong most often, and the way people get it wrong has killed divers. So we'll start there, then work through the gear.

What A Float Is Actually For

Four jobs, roughly in order of how much they matter.

• It makes you visible. A diver at the surface in a camo suit is almost invisible from a boat, and boat and diver interaction is a recognised hazard in Australian spearfishing. A bright float with a flag is what tells a skipper you're there.
  

• It saves your gun. Drop it, get it stuck in a bommie, or let go to deal with something else, and the line means you pull it back from the surface rather than diving to find it.
  

• It wears the fish out. A solid fish fights the float's buoyancy instead of your lungs, and you're not connected to any of it.
  

• It carries your stuff. A rigged float holds your catch, spare gear, water and a knife, and gives you something to hang off between dives.
  

On the visibility point, safe boating guidance for divers is worth reading properly if you dive anywhere near boat traffic, which in Australia is most places.

The One Rule That Matters Most

Do not attach the float line to yourself. Not to your weight belt, not to your wrist, not to a D ring on your suit.

The line goes from the float to the gun. That's the standard setup and there's a hard reason for it.

Why This Is Not Overcautious

Entanglement is not a theoretical risk. Divers Alert Network has documented fatal incidents where getting caught in kelp or line started the chain that ended in drowning, and their spearfishing safety guidance specifically warns about becoming tangled in your own rigging.

Experienced divers are blunt about it. One with years in the water put it plainly, saying a float line attached to the diver is asking for trouble, that everyone assumes they'll calmly unclip, and that this goes out the window fast once shock and panic arrive. He referenced deaths and near misses from divers caught in their own line.

Two things go wrong. The first is entanglement, in kelp, reef, structure or the line itself. The second is drag, where a wave pushes your float across a reef or a boat picks up the line, and suddenly something much stronger than you is pulling you somewhere you don't want to go.

If the line is on your gun, you let go of the gun. If the line is on you, letting go is not an option.

Where Guidance Differs

Worth being straight with you here. That the line should never be tied to the diver is close to universal. What the other end attaches to is less settled, and some safety bodies and instructors recommend different arrangements depending on conditions, including breakaway rigs and setups where the gun is not permanently tied into the system.

Kelp, poor visibility, heavy structure and strong current all change the calculation. Follow whatever your local training and conditions call for rather than assuming one rig suits every coastline.

The Honest Nuance

Some very experienced divers do clip on in specific situations, and pretending otherwise would be dishonest. One diver with four years at it described clipping the float to himself while swimming out from shore, in rough water and current, and when diving shallow, using a quick release arrangement rather than a clip.

Note what those situations have in common. Open water, no structure to snag on, shallow enough to matter less, and a release he can hit instantly. Note also that he unclips before he starts hunting.

There's a counterargument worth knowing too, that a line to the diver makes you easier for your buddy to track in poor visibility. The rebuttal from the safety side is better though. Use a high visibility snorkel, a bright knife holster or a hi vis patch on the back of your suit instead, and keep the line off your body. And if your leg is the thing that's tangled, ditching your weight belt can actually make it worse by pulling in the opposite direction.

None Of This Replaces A Buddy

A float is a piece of equipment, not a dive partner. Freediving safety guidance is consistent on never diving alone and working one up, one down, because shallow water blackout arrives without warning and a diver who blacks out cannot rescue themselves.

Your float will keep floating regardless. Only a person watching you can pull you out.

Choosing A Float

The bigger the fish you're chasing, the more buoyancy you want. For reef fish around Australian coastlines a standard torpedo float is plenty. If you're chasing tuna or big pelagics, you want serious flotation and often more than one float.

Whatever you choose, make it bright. Orange and yellow are the point, for the same reason your suit is camo and your float should not be.

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Float Lines And What They're Made Of

The line matters more than the float does, and the material changes how it behaves in the water.

The bungee point is worth understanding rather than just accepting. A stretchy line spreads the load of a fish's run over time instead of hitting the rigging with a single jolt, which takes strain off your gear and makes it less likely the spear tears free.

There's one material fact worth committing to memory, because it decides which line does which job. Polypropylene and polyethylene float, while nylon and polyester sink, because the first two are less dense than water and the second two are denser. Get that backwards and you'll have a sinking line where you needed a floating one.

How Long Should The Line Be

Run a float line comfortably longer than the deepest you plan to dive. Guidance varies on how much, with recommendations ranging from a few metres of margin up to half as much again, so treat a third longer as a sensible middle.

So if you're working 15 metres, something in the 20 metre range. If you're diving 10 metres, a 15 metre line is ample. One experienced diver described running a bit over a third more than his maximum depth as his standard, and that's a reasonable place to start.

Why not just go long. Because every extra metre is more line to tangle, more drag to tow, and more slack lying around you in the water. Too long is its own hazard, not a safety margin.

On diameter, divers who handle a lot of line tend to land somewhere around 8mm to 12mm. Thinner than that gets fiddly, tangles more and is harder to grip with cold hands or gloves. Thicker gets used for genuinely big pelagic work.

Rigging It Up

1. Float to line. Attach with a stainless clip and a swivel. The swivel is not optional, because a fish that spins will otherwise put every twist into your line.
   

2. Line to gun. Clip to the dedicated attachment point on the gun, usually a anchor point at the base of the handle grip, not to the line release or anywhere that fouls your shooting line.
   

3. Use rated hardware. Stainless clips and swivels rated well above what you think you need. Cheap hardware fails under shock load, which is exactly when you need it.
   

4. Check it before every dive. Clips seize, hardware corrodes in salt water, and line chafes where it meets the metal.
   

5. Keep it tidy. Coil it properly on the float. A bird's nest is a hazard, not an inconvenience.
   
   

Rigging is one of those things that's far easier to understand watching than reading, and there's footage of gear being used properly on our gear in action page. Our maintenance tips cover what to check and how often.

Drop Anchors And Taglines

Once you're past the basics, two extras come up.

A drop anchor stops your float wandering off in current, which is the difference between surfacing next to your float and surfacing a hundred metres downstream of it. A tagline lets you tie off to a pier pylon or similar structure.

The important part is that these are separate lines from your float line, and they want different materials. Your float line should float. Your drop anchor line should sink. A tagline for tying off to structure should float so it stays clear of what's below it.

Running one continuous line to do all these jobs is a rigging mistake, not a clever shortcut. Two lines that clip and unclip independently are safer, easier to store and easier to ditch in a hurry.

Float Or Reel

Reels split opinion and both sides have a point.

The case for a reel is that it's less to drag around, especially on a reef, and plenty of divers find them straightforward once they've got the hang of them.

The case against, at least early on, is line management. The risk is getting pulled down when something bigger takes your fish, or shooting into reef and kelp with a reel that keeps feeding line. Divers who've seen it happen tend to recommend starting with a float and line, learning how line behaves in the water, and adding a reel later.

Plenty of divers eventually run both, a reel for mobility and a float for visibility and for the days they're chasing something serious.

Kelp, Structure And Current

Rigging that works on open sand can be a liability in weed.

One useful technique from divers working heavy kelp is to clip the float to a strand of kelp and leave the end of the float line loose, rather than towing the float through the canopy. You have to swim back to it when you move spots, which is annoying, but it beats dragging a float through kelp and it keeps the line from wrapping.

Around structure, piers and bommies, keep your line short and know where it is at all times. Current is the other one. If it's running hard, a drop anchor is worth the extra faff.

Carry A Knife, Always

If you dive with a line in the water you carry a knife, and ideally a second one somewhere else on your body.

This is not about fish. It's about being able to cut yourself free from your own rigging, from kelp, or from someone else's lost line. The standard advice on cutting tools is that they need to be reachable even if one arm is restricted or entangled, which is exactly the situation you'd be using one in.

Mount it somewhere you can reach with either hand. On your belt or your calf, not buried in a float bag on the surface.

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What The Evidence Backs Up

• Entanglement kills. Documented fatalities involve divers caught in kelp and line, which is the whole basis for keeping line off your body.
  

• Boat strike is a recognised hazard, and Australian spearfishing bodies publish guidance on it specifically.
  

• Polypropylene and polyethylene float. Nylon and polyester sink. Straight density, and it decides which line does which job.
  

• Bungee lines really do reduce peak loading from a running fish, which takes strain off the rigging and the spear's hold.
  

• Spectra and dyneema are genuinely stronger per diameter than conventional rope.
  

• Swivels prevent line twist from a spinning fish, which is why they belong at both ends.
  

• Cutting tools should be reachable with either hand, per established diving safety guidance.
  

• Never dive alone. Shallow water blackout gives no warning and no chance to self rescue.
  

• One area where sources disagree. Keeping the line off the diver is near universal, but what the other end attaches to varies between safety bodies and conditions, so follow your local training.
  

What To Do Next

If you're setting up your first rig, keep it simple. A bright torpedo float, a float line about a third longer than your working depth, stainless clips and swivels at both ends, line to gun and nothing to you.

Floats and float lines are in floats, reels and fins, and the clips, swivels and rigging hardware are in accessories. Knives are something you should not be diving without one.

If you're building a whole setup from scratch, the speargun range is where the other end of that line attaches. Our piece on essential spares is worth reading before any serious trip, because rigging always fails at the least convenient moment.

For broader technique, have a look at our pro tips, and if you've still got setup questions our FAQ covers most of them.

The Short Version

• Line goes float to gun. Never float to diver.
  

• Entanglement and drag are the two things that kill people, and both get worse if you're attached.
  

• A float makes you visible to boats, which is its most important job.
  

• Run a line roughly a third longer than your deepest dive. Longer is not safer.
  

• Around 8mm to 12mm diameter suits most divers and tangles less than thin line.
  

• Polypropylene and polyethylene float. Nylon and polyester sink.
  

• Float line, drop anchor line and tagline are separate lines with different jobs.
  

• Swivels stop a spinning fish turning your rig into a knot.
  

• Carry a knife you can reach with either hand, and a backup.
  

• None of it replaces diving with someone who is watching you.
  

Rig it so that in the worst moment you can let go of everything and swim away.