• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Bluewater Pneumatics - Pros and Limitations

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
This is an interesting thought! But you can go the other way. Assuming that Sten parts are used, the size of the gun can be calculated proportionally.
I also have a photo and one cannot doubt its enormous size.
 
Yes, I know John Warren, he built the “Supergun” to explore the possible limits of speargun technology. The gun uses a modified Prodanovich handle in order to take the enormous load (in excess of 1000 pounds) on the trigger when the bands are cocked using a block and tackle winching system. The handles on the sides of the gun are to help in manoeuvring it around and the glassed foam flotation gun body has a thick stainless steel tubular spine. The gun is fully ballasted and very powerful, but was not intended for long term use as other less ambitious designs based on the Prodanovich system could do the job and are much faster to load. Even when game spearfishing for Tuna and Yellowtail you don’t need a Tiger Tank!
 
Actually the real limitation on guns is the effort involved and the time it takes to reload given the hunting situation. If you just need one shot and are jumping into the water from a vessel that has just teased up a Tuna or Marlin using trolling lines then a powerful gun can be used as you will not need a reload. If you miss the fish may be gone, so plenty of time before the next one. But if you are taking lots of shots with plenty of fish around you want to be reloaded in a minute or so, or even less if you can forego rigging the line. You can do that with a pneumatic as you just ram the shaft in, throw the line to the side and pull the trigger. On a band gun you need a closed muzzle to do this.
 
Hey all, so I'm doing some research into bluewater guns and a friend mentioned getting a pneumatic. I came upon this thread and after reading it, couldn't quite tell whether a pneumatic would be recommended for bluewater situations or not... I was contemplating a 130 roller/double roller and would want something with the range and power of that. Would the Salvimar Predathor Vuoto 130 be a good choice for taking down tuna up to 100 lbs (50 kgs) or so? It also seems like loading a long gun like that is a hurdle for many and I'm only 5'7" (168 cm) tall.
 
Reactions: Diving Gecko
You can use an extended loader to load a long gun. Check out this video of the Omer extension loader. Mares also make one called the Long Clever loader.
 

Not a hurdle but sadly, a lot of “urban myths” surrounding airguns.
We are the same height and I can load a 135 gun easily with an extended loaded - if the pressure is not too crazy.

I would trust a 135 with an 8mm shaft and slip tip to take down 50kg tuna. But consider getting a UBL Muzzle set as the piston and shock absorber can take a beating and his slide rings are super strong and minimal size. But it can be a real hassle ordering from him and even worse now that he is in Belize and the pandemic doesn’t help.

That said, a Predathor at more normal pressures of 22-25 bar should be alright too. I did see a broken shock absorber on one running 28bar but maybe that one was a fluke.

Gazz will hopefully weigh in on this as he shot a 135, I think, at normal pressures quite a lot.

One thing to keep in mind is how big an effect the shooting line has on the speed of the shaft. I think with a thin dyneema or mono you’ll be alright with an 8mm shaft but if you’re talking dogtooth tuna then you need to up the shooting line and my personal thinking is that an 8mm shaft at 22-25bar starts not having enough energy in it to carry the heavier tackle. But if it’s a tuna that heads for horizon rather than the bottom you can downsize the line and I would think you’ll be alright.


Sent from my iPhone using Tapatalk
 
Last edited:
Reactions: foxfish
Pelengas make an extended loader which used to be supplied with their longest guns, but now you can buy it as a separate item.

Shaft Loader For Speargun Longer Then 120 sm | eBay

Find many great new & used options and get the best deals for Shaft Loader For Speargun Longer Then 120 sm at the best online prices at eBay!
www.ebay.com.au
The capped tube type loader is very good as you can slip it over the tip and it will stay in place as it lays on the spearhead and it can be removed while keeping your hand well behind the pointy end.
 
Last edited:
Awesome and thanks! The tuna here are primarily yellowfin, so could probably stick to mono shooting line. Is the predathor a good gun to get? Looks like the 130 comes with an 8mm shaft so could be ready to shoot without any additional mods. Any thoughts or other recommendations? Also, most people here use slip tips and breakaways, would that be possible with pneumatics?
 
I suggest you shoot a few other fish with the pneumatic before you have a crack at Tuna in order to familiarize yourself with the gun. The Predathor Vuoto guns are supplied with spring stainless steel fixed flopper shafts (integral tips). Salvimar also make threaded tip shafts, but these have 7 mm threads. While they offer slip tips they are for their band gun line, you can check these in their catalog which is available on-line. Pelagic fish like Tuna unless disabled instantly want to swim off with your gun, so a break-away rig is a good idea. A reel can have a lot of line on it, but it can disappear pretty quickly if your fish is still swimming properly. Most speartips are threaded for 6 mm, so you would need an adaptor for using such tips on pneumatic shafts. There no doubt have been pneumatic gun spears made with 6 mm threaded ends, but they are not easy to find. A machine shop could rethread shafts for you, the main thing is the thread is cut straight to the axis of the shaft as that ensures the tip screws on straight.
 
That's the thing, here in the northeast US, there aren't really any opportunities (mainly poor viz... e.g., ~10ft) to shoot fish with such a big gun other than far out into the ocean where the tuna are. Maybe it's worthwhile for me to get a 55cm gun to actually use and familiarize myself with the gun and technology? And for a slip-tip, maybe worthwhile to use one of these - Kimera slip-tip, as I could easily convert the supplied 8mm flopper shaft without worrying about machining, etc?
 
Last edited:
Super! Question though is whether a 7mm shaft would have enough mass and energy to hit and penetrate a 50kg fish with? I've heard the shots are sometimes far and would probably need to put extra pressure into the gun for the extra range. From what I've read about double rollers is with the extra energy, extra mass is needed to stabilize the shaft. Is this also the case with a pneumatic gun?
 
Reactions: Diving Gecko
7 mm is the thread size, the shaft diameter is 8 mm. The smaller Vuoto guns from 100 cm down have 7 mm shafts, the 130 cm has an 8 mm shaft.
 
Last edited:
Many years ago spear shafts were produced with an alignment shoulder behind the threaded tip on the shaft. This matched a skirt at the rear of the threaded hole in the tip so that it pulled up straight when tightened up on the shaft. Imperial sizes were most common, so 5/16" shafts had 1/4" threads and 3/8" shafts had 5/16" threads. As 1/4" was a bit small all shafts soon adopted the 5/16" threads. Then 5/16" was replaced by 6 mm metric threads in recent years. Pneumatic spearguns with a few rare exceptions have always been metric, hence the pneumatic guns shafts used 7 mm threads whether on 7 mm or 8 mm diameter shafts. There have been 9 mm diameter pneumatic gun shafts, these usually have 7 mm threads.
 

No to 7mm and I rarely rule out things that categorically here.
But here’s the deal; a shaft for a 135 will only be around 145cm which is about the same as a 105-115 bandgun. So, it’s basically a very short shaft.
Hence why I say you need 8mm plus the thinnest mono you can get away with or at the most 1.4mm stiff dyneema.

I shot 10-20kg dogtooth in Indo with an 8mm slip tip shaft of around 145cm length and would have taken a shot at 40-50kg fish had I seen one and had it come close enough. I had about 33bar in my gun and it was enough to power that shaft up rigged with 1.7mm stiff dyneema but you won’t get to those pressures with the Predathor. Hence why you need to rig it lighter and make sure you don’t take long, Hail Mary shots.


Sent from my iPhone using Tapatalk
 
Last edited:

As for the double rollers, I have a bit of doubt about the explanation on shaft mass you presented;-)
It’s more likely that the big rollers were designed to hunt tuna and dogtooth and you need mass and speed in the shaft for penetration and to pull the shooting like. And that dictated the power needed. Also, rollers are sometimes shorter so shafts had to be thicker to still have enough mass.


Sent from my iPhone using Tapatalk
 
If I need to take 20-25 ft shots on ~70lb tuna, would the 130 predathor be able to since you said it couldn't go up to the higher pressures? I was also considering a 120/130 inverted roller for the same purpose. Worst case, I would probably still get a 155 classic setup wooden gun.
 
Do you think you will need that range to shoot Tuna? A fast water column swimming fish, unlike Dogtooth Tuna which tend to hang around near the bottom, Tuna present a difficult target unless you know they are heading for something if you shoot from a long way out. 20 feet is a long shot underwater.
 
From what I've heard, yes, but not from direct experience. I've heard they're more wary here and often time you'll need to take those longer shots and to take that into consideration, e.g., aiming and shooting just ahead of the fish. It's been recommended to get the big wooden guns (150-170), but I was hoping to get something a bit more compact, so therefore the look into pneumatics and rollers.
 
I suggest that you accompany someone on a Tuna hunt and see what is involved before doing anything else, the capabilities of the hunter and the gun and the capture gear that goes with it all combine to make the enterprise successful. Tuna are strong enough to give you problems as unless stoned they don't come along quietly, which is the same for any big pelagic fish.
 
Reactions: marco15499
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…