Spearfishing, Broken Finger

[Walter]

"The wire attached to the elastic is going to be pulled through one hand or the other when the elastic breaks--nasty."

Over the years, I've had lots of bands break - either in my hands or in the hands of my buddies. I've never seen what you've described occur.

 

[Laurence Stein DDS]

Walter, I've seen it happen to my buddy twice. It didn't require stitchs but it well could have. He was using an arbelet and the piano wire on the elastic broke while he was cocking it. Made a mess. The stress must have concentrated in the wire where it curves around the notch in the spear--this is where it broke--metal fatigue.

I know some of the better guns have a "swivel" device in the wire and this probably helps prevent breakage at the notch. The elastics can still break and if you think getting snapped by a rubberband is bad, having an elastic shoot through your hand doesn't feel so great--even if it doesn't cut you up.

Larry Stein

 

[FredT]

Larry, a short gas gun is a better choice for fish in rocks, a band gun of considerable length pretty much the only choice for larger fish in open water. Gas guns tolertate a bent shaft very poorly. I can restraighten a pretzled band gun shaft and keep hunting. ANY bend in gas gun shaft is intolerable as the shaft will tend to hang in the gun. Yes, I have seen both types where the tip and the catch end of the shaft are pointing the same way, and a few that were looped a few times along the way. A short gun makes shaft bending not as much of an issue, but a longer shaft with enough momentum to be useful on a 60 pound fish will bend up in a heartbeat.


A pneumatic gun with 500 psi working on a 1/2" diameter piston is pushing a shaft with a little less than 100 pounds force. My main rig gun has 3 120 pound force bands. A missed shot does damage to to the line attachment hardware, but it'll toss a shaft clear through 18" of fish skull. If I hit the rig the tip will bury into the steel leg of the structure about 3/4" deep, much like a powder actuated concrete nail gun. The tip will have to be removed or broken off to recover the shaft.

BTW if the band is properly rigged a broken wishbone is not normally a problem. This is one reason why we wear GLOVES! Fish teeth and gill rakers are another. The main pain with a band gun happens when a 120 pound tensile band breaks at the muzzle end. Only one thing that has happend to me underwater has ever hurt so much, including having a man-o-war inserted into my wetsuit by a breaking wave. The exception was a significant bristle worm hit. I'll push wishbones and bull rings, but a band worn enough to _maybe_ break at the muzzle is replaced ASAP.


FT

 

[Laurence Stein DDS]

Fred T,

I agree with most of what you said.

My buddy and I both wear gloves for protection for a variety of things including injuries from sharp surfaces from the spear.

My gun with 500 lb/in sq and a 1/2 sq in surface has 250 lbs of force on the base of the spear shaft. That pressure, for practical purposes is applied through the entire shaft acceleration--to a very high speed. As you have mentioned, a bent shaft on a pneumatic gun is a real problem. The slightest bend causes the shaft to veer off in a different direction--because of its speed. It is impossible to straighten a bent shaft so it is accurate again. Spring steel is the only way to go--to avoid bends--and they still happen.

A band gun on the other hand, has a tremendous amount of force applied to the shaft in the cocked position. If you will allow for a simple assumption (which is not quite exactly correct near the ultimate strength of the elastic), as the elastic contracts to half its cocked length, its force is cut in half as well. At the point that the elastic is completely relaxed, it is applying NO acceleration to your shaft. The force applied to a shaft of a band gun falls off very rapidly when it is fired. This the reason for using longer guns and longer spears. The pneumatic gun is still accelerating the shaft when a band gun is letting the shaft coast.

The ultimate speed of a band gun spear is less than that of pneumatic gun--even if the pneumatic gun has less potential energy being applied to the spear prior to its release. Certainly, this is a generalization because if you routinely keep low air pressure in the gun, no amount of acceleration will cause the speed of a pneumatic spear to exceed a band spear.

I also have the problem of impailing a shaft into metal or rock. For me, the best shot distance is just as the spear releases from the barrel. My shaft is shorter and it loses momentum faster than your band spear. At short shot lengths, the gun is nearly silent. If I take a long shot, the piston slams against the piston stop and makes a loud noise. There is almost no noise at low power.

Your band gun is best used in open water for large game. My gun is best in close quarters like a wreck or reef. Even when set on low power, at depth, a close shot can penetrate many inches of fish. At high power, it can penetrate the entire length of a large fish--as your gun can.

Another advantage to my gun is that I can switch to low power and unload the gun--leaving it in an easy to cock condition. Recock and switch the power switch, and you have full power again. You, on the otherhand either take a full power shot to unload or grasp the elastics and remove them--something I feel is risky--especially on a long gun.

Bottom line is we like what we have gotten used to. I've used both and appreciate the incredible accuracy of the pneumatic. I am always amazed by the quietness of the band gun--especially A.B. Biller and Riffe guns. They are well engineered and "throw" the spear nearly perfectly straight. Some of the all metal guns tend to under shoot because the band "Y's" are slightly above the shaft and the elastics are even higher. They tend to pull the rear of the shaft upwards. The better guns have a track that keeps the spear rise to a minimum.

Like I said before, I also appreciate the speed that a pneumatic can be reloaded. You don't have to look at anything except your target. Everything can be done by feel. You don't even have to restring the line if a quick shot is needed.

Slipping the spear UNDER the bands and into the trigger housing with the spear notch alligned with the sear mechanism requires looking at the gun for a moment. The line cannot be wrapped around the elastics and the shaft must be under the bands. Commonly, the bands following a discharge are on the "other side" of the gun and must first be flipped upward before the insertion of the shaft. Failing to do so makes it impossible to load the gun and tangles the line.

Actually, we pretty much agree with each other as to the merits of each gun. Check out my photo on my personal page--it's a 35 lb cobia--one shot, no help. This is one of the most powerful fish in the ocean. They are almost impossible to boat because they are so strong. The pneumatic made it easy.

Regards,

Larry Stein

 

[The Chairman]

If the shaft is 1/2" as they are... then the area is only 0.25 square inches, and the force applied would be 125 lbs (less any losses). Remember the old lie... Pie R SQUARED!!! You gots to square the 0.50"

 

[Laurence Stein DDS]

NetDoc, thanks for checking my math...HOWEVER, I didn't say the shaft was 1/2 inch. I said that 500 lb/sqin was applied to the base of my spear (shaft). It turns out that the base of the shaft is nested in a piston that has approximately 1/2 square inch AREA. Therefore, there is approximately 250 lbs of pressure (force) being applied to the base (area) of the piston and THAT is used to accelerate the spear shaft. The spear shaft never actually comes into contact with the compressed air but it is accelerated by that forceut:.

Even if the lower number you provided was used, for practical purposes, that force is applied throughout the spears acceleration. The volume increase within the barrel is minimal compared to the reservoir volume. The spear is accelerated at the beginning AND the end of the stroke. A band gun's acceleration rapidly decreases to zero and that occurs even before the shaft leaves the gun. The maximum velocity of a pneumatic spear is very likely to exceed nearly any band gun except, perhaps, a very long gun with humongous bands.

I stand behind my original calculations. Thanks for your help. I believe you Pi is done!

Larry Stein

Heh, heh, heh, Pete you're not wrong often but this time....I just can't stop laughing!

 

[raffles]

Now for something controversial!

I think that all this B******* attempting to make spear fishing on scuba appear a technical sophisticated sport is a desperate attempt to hide the fact that it is reeedickulussly eeeasy to slaughter fish while wearing scuba.
Last time I said that in a Bar the "sportsmen" took umbrage and pointed out that the take gets harder to find and smaller every year. No Duh!
If you are all free diving for your take then I apologise but if you're not then YOU are part of the reason than fish stocks world wide are dissappearing don't try and justify it YOU ARE. Just stop and think that "my small take is unimportant" multiplied by supposedly thousands is as big an impact as "commercial" takes:boom:
as for pointing loaded weapons at each other sounds like there may be a Darwinian process in action that would be seen by some as well deserved

:bonk:

 

[Laurence Stein DDS]

Raffles,

Ya know, you're right. Scuba diving and spearfishing IS easy but limited. You generally will dive a wreck or a reef. Certain types of fish are very easy to shoot. BUT....try to catch fish that are familiar with divers, that are spooked by the sound of the regulator, that are being chased in a current and the chance of getting even one fish on any given dive is low.

I've spent a lot of time free diving and spearfishing. I always catch more free diving because I can drift for hours and cover huge amounts of bottom.

BTW, this thread is NOT about the making spearfishing technically sophisticated. It just happens that in the course of the discussion, the merits of different types of spearguns appeared.

I might also add two other small items...to think about... First, where I live (Miami), it is not uncommon for anglers to brag about finding a "grouper hole" and catching a staggering number of fish. They may use wire line and a winch. THIS DISCUSTS ME! These anglers ARE NOT SPORTSMEN. I eat what I catch, period. Second, I have visited the Caymens since I was in college and that is a long time ago....there USED to be a lot of a wide variety of fish there. It was SOOO long ago that there were no dive boats! My father and I hired a local boat and some "guides" call Ebanks (the island is covered with Ebanks) and were were able to freedive and...(ready for this?...SPEARFISH!)--that's how long ago it was! The last time I visited, ( and that was a while ago) I was astounded by the LACK OF EDIBLE SPECIES on the commonly dived wrecks. Since the visiting scuba divers cannot catch them I suppose the locals have managed to clean out the shallower areas. Are you going to blame divers and spearfishing for this?

Even with replentishment areas, the Caymens, especially, Grand Caymen is OVERDIVED AND HAS BEEN OVERFISH BY THE LOCALS.

Scuba diving and spearfishing may make it easier to catch one fish at a time but why not get off your high horse and recognize that anglers and commercial fishermen are most likely responsible for the greatest damage. Direct your comments at the real source of the problem.

While you are at it, perhaps you can explain why on the wreck such as the Oro Verde...used to COVERED with snapper, grouper, hogfish, you name it. I know I saw it 30 years ago and I have seen it recently. The fish are sparce and if you are lucky you will see Sweet Lips or some of its friends. The wreck's condition now is a crime and you really can't blame spearfishing OR anglers. Blame the thousands of DIVERS who dive and touch and stir up the bottom--the fish have left in DISCUST!

I have no real desire to visit Grand Cayman anymore. It's too commercial and the area is truely overdived.

There is much more at work here than spearfishing. Perhaps it would be good for you to redirect some of you ecological energies into finding the real culprits.

Finally, don't blame the "messangers". Those "sportsman" at the bar ARE telling you something. The fish ARE dissappearing. Instead of starting at the bottom of the food chain, direct you attention to the commercial catch, to anglers that come back with hundreds of pounds of fish---they must have really big appetites! Yes, spearfishing, catching one fish at a time, contributes to the decline but I think you may have gotten it bass ackwards. Start with the big guys first and question the reasons why totally protected areas also are in decline.

I have to go and catch a fish.

Regards,

Larry Stein:banging:

 

[The Chairman]

I think that all the fish caught by all the spearfisherman in the world for a year, pales in comparison to what is taken by come commercial fishermen in a day! No, I don't spearfish... I only correct their math! :tease:

 

[Laurence Stein DDS]

Amen, Netdoc, amen.

Larry Stein