Speargun Shaft speeds vs the sound of gun

  • I posted this on HSD, and got JUST 1 reply... Anyway


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    Hello all.


    I've read lots of chatter on various forums about the spear gun shaft speeds and the such.


    But I've seen very little dialog about the sound of the gun and it's impact on the target fish.


    From what I've read a typical shaft goes from 25 - 29 m/sec ( ~ 60 mph) so it's humming along. But the speed of sound in water is much faster than in air. Typically 1,550 m/sec not accounting for water temp.


    So anyway, Is a the noise of the gun a factor? Are some more noise dampened than others? Is this considered in the design phase?


    I read about getting faster shafts and U-tube videos on fish dodging, Matrix effect, but seems to me the sound is the warning vs the other stuff.


    Perhaps I'm all wet on the topic. Love to hear what you guys think.
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    I know Pete will post on this one.


    -John

    Edited once, last by Linghunt ().

  • Linghunt--
    "So anyway, Is a the noise of the gun a factor?"
    Yes
    "Are some more noise dampened than others?"
    yes, generally speaking, wood guns tend to be quieter.
    "Is this considered in the design phase?"
    yes, to the extent that there has been great discussion as to how to suppress the noise generated by the speargun mechanism, as obviously the very first noise that a speargun generates is the mechanism working to release the spear/bands.
    hope this helps

  • Hau,


    Yep, yep. I will bang on the rocks on the bottom at times to attract Ling-cods in. Throwing the anchor off the boat and noise hitting the bottom works too. Usually something there when I follow the rope down to check placement. I always check the anchor with a gun loaded.


    I brought this up, since there was limited chatter on it. The speed of sound in Water is so much faster than in Air, thought it would good for fellow spear-o's to think about it. 5000 ft/sec is smoking fast.


    The sound can also be a positive as another thought. Any time I was hunting on Scuba, kind-a felt like I was hunting with a loud chainsaw on my back from the noise of the regulator.


    The Speed variation based on Water Temperature was a something I forgot about from School days.


    % wise, not really a factor, but interesting still.


    Here is a reference with nice graphs.


    Water - Speed of Sound

  • From my point of view, it's not so much how fast the sound travels, since it's moving way faster than the spear. Rather, it's whether the fish tries to spook, and whether it can react fast enough to affect the impact point of the spear. I don't think you can make a gun quiet enough for a fish not to hear. It's well recognized that bubbles from SCUBA , or noise from bubbles, makes fish wary, and yet most of us have probably used a fish's curiosity to entice it out of a hole by rubbing the point of our spear in the sandy bottom. So, I think they hear (feel?) any noise that we are aware of, it's more a question of whether it spooks them, and if so, can they move fast enough to react and move out of harm's way in about .16 seconds. I suppose it depends some on the species, as well. I hunt mostly snapper and grouper- which move at glacial speed compared to wahoo or tuna. So, I think in every case the fish hears the shot since no gun is completely silent, it comes down to whether he wants to, or can, move quickly enough to affect shot placement. Make any sense? :rolleyes1:

  • From my point of view, it's not so much how fast the sound travels, since it's moving way faster than the spear. Rather, it's whether the fish tries to spook, and whether it can react fast enough to affect the impact point of the spear. I don't think you can make a gun quiet enough for a fish not to hear. It's well recognized that bubbles from SCUBA , or noise from bubbles, makes fish wary, and yet most of us have probably used a fish's curiosity to entice it out of a hole by rubbing the point of our spear in the sandy bottom. So, I think they hear (feel?) any noise that we are aware of, it's more a question of whether it spooks them, and if so, can they move fast enough to react and move out of harm's way in about .16 seconds. I suppose it depends some on the species, as well. I hunt mostly snapper and grouper- which move at glacial speed compared to wahoo or tuna. So, I think in every case the fish hears the shot since no gun is completely silent, it comes down to whether he wants to, or can, move quickly enough to affect shot placement. Make any sense? :rolleyes1:


    And, will he move out of the way or into the shot?
    I have shot at fish that were broadside shots only to end up with a fish kabob, speared right down the length of the spine. On longer than normal shots I will mentally adjust slightly favoring where I think the fish will go to flee from the threat, me.


    I find it more of an issue with pelagic fish as they will bolt and leave while a lot of reef fish will stay in the area and sometimes not leave at all, returning right away to the their same crack or hole.

    i like to spear fish

  • Bottom fish can move fast enough to be skewered twice by one spear.


    As a rule if you shoot at a fish that's facing you directly, you'll end up with a side shot fish.


    Sometimes i think its actually the spear that moved faster. As for fish facing you directly...its only the fast ones that make you end up with a side shot. I use that to my advantage when hunting some of those super quick cuberas we have here. Its always a better shot when you could get them facing/coming at you...unless they teleport :nana: :outtahere:

  • Mangrove snapper, I aim between the eyes, and hit them behind the gills. Red snapper, If I aim between the eyes, I hit them between the eyes. I guess red snapper are not as smart. I shoot some noisy guns, my dive buddies tell me so often. Pneumatics, Aluminum Euro guns, and now a Co2 powered gun. (I don't like wood). I don't have issues with fish leaving before the spear gets there.


    KC

  • Mangrove snapper, I aim between the eyes, and hit them behind the gills. Red snapper, If I aim between the eyes, I hit them between the eyes. I guess red snapper are not as smart. I shoot some noisy guns, my dive buddies tell me so often. Pneumatics, Aluminum Euro guns, and now a Co2 powered gun. (I don't like wood). I don't have issues with fish leaving before the spear gets there.


    KC


    This thread was more for general education. But you gave me an idea.


    Wonder if we can gather info , on which type fish are more jumpy than others. Not sure how to measure metrics of each type and then Data is diver opinions. Maybe someone has some thoughts on this.

  • the wsb in my avatar was swimming left to right when i pulled the trigger but the shaft hit him with a right to left hit (you see the exit side in the pic )


    phil

  • How far away was the shot Phil? That is a lot of fish to turn fast.


    To the OP, I think the noise definitely makes the fish move but the completely random nature of the movement is the X factor. I guess a quieter gun is better because it might be less alarming. I notice no differnce in fish behavior between my rob Allen and my wood gun. Wood gun is way quieter but the bands still make such a force I always figured the fish heard that more than the shaft on the track

    i like to spear fish

  • How far away was the shot Phil? That is a lot of fish to turn fast.


    To the OP, I think the noise definitely makes the fish move but the completely random nature of the movement is the X factor. I guess a quieter gun is better because it might be less alarming. I notice no differnce in fish behavior between my rob Allen and my wood gun. Wood gun is way quieter but the bands still make such a force I always figured the fish heard that more than the shaft on the track


    15' or so ,' wsb are very flexible, and very fast , that particular fish was just cruising with a school and in no way on edge when i pulled the trigger , i didnt know it turned until i looked at the pic later on

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