Bluewater speargun guide

Short answer: a bluewater speargun is a long, powerful gun built to reach pelagics in open, clear water and stop them cleanly. For most Australians that means 120 to 140 cm and up, a 7.5 to 8.5 mm shaft, multiple bands or a double roller, a slip-tip, and a proper reel or float system. The gun is only half the setup. Out wide the rigging around it decides whether you land the fish or watch it swim off with your shaft. Here is how to put the whole package together.

What makes a gun a bluewater gun

Bluewater hunting is a different game to reef diving. You rarely get close, so you need range and shaft speed to reach a fish that will not let you inside 4 or 5 m. You are also shooting fish that can weigh 20, 40 or 100 kg and swim hard, so you need penetration to punch through and a system that holds them once you connect. That points to a long barrel, plenty of stored energy in the bands, a heavy shaft, and a way to stay attached, which is where slip-tips, reels and floats come in.

Length also buys you a flatter trajectory and more forgiveness at distance. A 130 cm gun keeps the shaft on line further out than a 100 cm reef gun ever will, which matters when a wahoo gives you one chance at 4 m and quartering away.

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Choosing your length

Pick the length from the fish and the water you actually dive, not the biggest gun on the rack. A cannon you cannot track is slower onto the fish than a gun that fits you.

110 to 120 cm (light bluewater, clear-water reef edges): smaller pelagics, wahoo, mackerel, kingfish and small tuna where visibility runs 20 to 40 m. A strong crossover choice if you split your time between reef and the blue.

120 to 130 cm (true bluewater all-rounder): the length most Australian bluewater hunters settle on. Enough reach and power for the majority of pelagic work without being a chore to swing and reload in the water.

140 cm and up (big-fish specialist): reserved for serious tuna, big Spaniards and dogtooth in gin-clear water, usually with a reel or a big float setup. It is a specialist tool, not a first gun.

Railgun or roller for bluewater?

Both work out wide, and the right pick depends on how much power you want and how much upkeep you will do. A powerful railgun such as the Vendetta King or King Venom is simple, tough and easy to service, and with the right shaft and double bands it has the range and punch for most pelagics. A roller, and especially a double roller like the Vendetta Double Roller, holds power through more of the shot for a flatter, harder-hitting result, which is a real advantage on fast fish at distance. The trade-off is a slower load-up and a little more maintenance. If you dive the blue often and want the best ballistics, go roller. If you want a rugged, no-fuss reach gun, a big railgun still does the job.

[tip]Match the shaft to the fish, not just the gun. A 7.5 to 8.5 mm shaft resists bending and holds a slip-tip better than a thin reef shaft, and it is cheap insurance against losing a fish of a lifetime.[/tip]

Rigging that lands fish

Out wide, the rigging is what turns a good shot into a fish on the boat.

Slip-tip. A flopper holds smaller fish, but a big pelagic will tear off or bend a fixed flopper on a shaft. A slip-tip toggles behind the fish and turns sideways under load, spreading the pressure and staying put. For anything over about 10 to 15 kg it is close to essential.

Reel or float line. A reel keeps you mobile and is neat for boat diving, while a float line and buoy let a big fish run against buoyancy and tire itself out. Many bluewater hunters run a bungee and a hard float for the biggest fish. The reels, fins and floats collection has the options.

Fins and freediving kit. Long-blade fins, a low-volume mask and a comfortable, correctly weighted setup all matter more the deeper and wider you dive. Bluewater is freediving first and shooting second.

Banding and power

Bluewater guns carry more rubber than reef guns, either as double or triple bands on a railgun or as a double roller. More power means a harder load, so build your loading technique and strength before you jump to the heaviest setup. Over-banding a gun you cannot load cleanly costs you accuracy and safety and gains you nothing. Our rubber size chart lays out band diameters by gun and target, and the safe loading guide covers technique for multi-band guns.

Know the rules before you go wide

Spearfishing law in Australia controls where you dive and what you take rather than the length of your gun. There is no national limit on speargun length, but sanctuary zones, restrictions near swimmers and infrastructure, and species protections all apply out wide as much as inshore. Scuba spearfishing is banned in many areas, so bluewater hunting is freediving only in most places. Confirm your local rules before each trip through the relevant state fisheries authority, and check bag and size limits for the pelagics you are targeting.

Building up to it safely

Bluewater diving carries real risk. You are often a long way from the boat, in deep water, holding your breath after a heavy load-up. Dive with a buddy on a one-up, one-down system, know your limits, and build depth and breath-hold gradually with proper training. A shallow-water blackout does not care how good your gun is. Treat the freediving skills as the foundation and the gun as the tool that sits on top.

The short version

For most Australian bluewater hunting, a 120 to 130 cm gun with a 7.5 to 8.5 mm shaft, a slip-tip and a reel or float system is the sweet spot, and a double roller like the Vendetta Double Roller gives you the best ballistics if you dive the blue regularly. If you are still choosing between roller and rail, or unsure on length, our speargun size guide and best roller speargun guide break it down further. Our team dive these waters themselves, so if you want to talk it through before you commit, get in touch.

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