Electric eels are animals that eat by stunning their prey with electricity before eating them. The amperage and voltage isn't usually high enough to kill humans but it can still hurt them.

Assuming there exist merpeople who are the same size and mass as humans but live in the sea with fish tails, would electric weapons be practical for them? Outside of tasers, electric weapons aren't common in the real world because there are generally more efficient ways of harming people. The ocean is a completely different environment however, and guns are less effective underwater. If the merpeople are just as intelligent as humans and have access to 21st Century technology, could they build some type of electric rifle? If so, what would it look like, would it have a large effective range, and would it be practical for infantry to carry?

  • $\begingroup$ What is an electric rifle that is not a taser? $\endgroup$
    – L.Dutch
    Jul 21, 2022 at 18:53
  • 1
    $\begingroup$ Electric eels don't live in the ocean. They're freshwater fish. (They're also not eels.) The Torpedo Ray is a saltwater electric fish. $\endgroup$
    – jdunlop
    Jul 21, 2022 at 18:58
  • $\begingroup$ @L.Dutch a taser is a small weapon meant to stun instead of kill. Electric eels can also stun nearby prey without directly touching them although contact helps. $\endgroup$
    – ITM_Coder
    Jul 21, 2022 at 19:01
  • $\begingroup$ For this question to be answerable you're going to need to tell us what electric weapons actually are in your world and how they work. In the body of the question it looks like you're also asking us to figure that out. We have a strict 1 question per post rule on this site. You're asking at least 3. Furthermore we aren't a brainstorming site and you can't ask us to generate ideas about how something could work in your world. $\endgroup$
    – sphennings
    Jul 21, 2022 at 19:09

5 Answers 5


There are a lot of questions here, but I'll answer what appears to be the primary one: could there be an underwater electric rifle.

Yes, but not in the way you think

Water has pretty high impedance. Even saltwater isn't a spectacular conductor (when compared to various metals). You have to be within about 20m of a lightning strike in the ocean for it to likely be lethal. So if you're envisioning a rifle spitting electricity, that's not going to work.

What you will have is effectively a taser speargun/torpedo. An aquadynamic projectile capable of triggering an intense electric charge is launched via compressed air from a rifle, and then activates an internal propulsion system, triggering its charge either a set time from launch or on contact. The possibility of friendly fire in close combat would be extreme, if you're delivering a voltage/amperage combination that can kill despite the combatants not being grounded, so this would strictly be a ranged weapon, discarded once people closed to knife range.

This also would be a very expensive projectile, so trigger discipline would be key.

  • $\begingroup$ If a post has a lot of questions it should be closed as needing focus until edits are made not answered. $\endgroup$
    – sphennings
    Jul 21, 2022 at 19:11
  • $\begingroup$ This fixes the issue that I brought up in my answer. I hadn't thought of attaching an electric charge to an aquadynamic projectile. This does, however, raise the question of whether or not the projectile is rechargeable. If it is, then the mer-people can go collect the projectiles after a battle and recharge them for further use, making them far less expensive and more usable as a multi-shot weapon. Then, also, are there artillery versions of this weapon with larger payloads and range? $\endgroup$ Jul 21, 2022 at 19:32
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    $\begingroup$ @shootbuildthink - artillery versions would suffer from diminishing returns (see the reference to lighting strikes in my answer). For artillery, they'd just use torpedoes. Water may not be a spectacular conductor of electricity to ground, but it is uncompressible. The shock wave from a torpedo detonating would pulp a lot of important bits inside any nearby merpeople. $\endgroup$
    – jdunlop
    Jul 21, 2022 at 20:45

could they build some type of electric rifle?

Neither projectile weapons not electrical charges work very well under water.

would it have a large effective range,

It would not.

Tasers, and the attacks of strongly electric fish, rely on using electrical fields to stimulate a target's muscles. Fish do this by getting close to their targets, and in the case of some electric eels, wrapping their body around the target to maximize the strength of the electric field. This is obviously quite short range,

Tasers solve this by shooting out two conductive probes over a relatively short distance, with an electric source at the gun end, or by shooting out a self-contained projectile that carries its own conductive barbs and power source.

Problem is that shooting projectiles through water is pretty challenging. Obviously spearguns exist, and even underwater firearms, but their range is pretty disappointing compared to above-water weaponry. Because of the rapid drop-off in speed caused by the much higher drag forces experienced by underwater projectiles, any taser-like weapon risks being deadly when used at close range without additional (complex, possibly unreliable) mechanisms to adjust muzzle velocity.

There are other things you might consider.

One is the use of self-propelled projectiles, possibly mini rockets or hydro-ramjets or mini torpedoes. Such things might be able to carry single-use electrical warheads, like the taser shotgun shell, if what you wanted to do was to stun or incapacitate rather than maim and kill.

If you wanted a deadly weapon, and your question implies you might even if you didn't outright state it, then honestly there are better options out there. Fitting your miniature torpedoes or rockets with explosive warheads is pretty effective... fragmentation obviously doesn't work well underwater, but concussive shock is much more effective thanks to water's density and high speed of sound. Small explosive warheads might also work as "less-than-lethal" weapons, stunning and disorienting and deafening but not necessarily killing. Contact warheads like powerheads, or simply compressed air injectors would also be highly effective (and appear to have been at least researched and built by cold-war era militaries).

Electrical stuff isn't going to be any more compact or convenient than these options, so unless you specifically wanted to keep your targets alive and intact whilst briefly incapacitating them it isn't clear what benefit it has.

  • $\begingroup$ Would a handheld weapon that shoots torpedoes be feasible? $\endgroup$
    – ITM_Coder
    Jul 21, 2022 at 20:05
  • $\begingroup$ @ITM_Coder Sure; if you're already storing a substantial electric charge, an electric motor wouldn't be much of a problem. You wouldn't have bullet speeds, but you wouldn't have bullet speeds regardless of the option you choose. $\endgroup$
    – jdunlop
    Jul 21, 2022 at 20:50
  • $\begingroup$ (Also +1 because this points out that if all you want to do is kill merpeople, electrical weapons offer no advantage.) $\endgroup$
    – jdunlop
    Jul 21, 2022 at 20:56

In short, such weapons would not be feasible.

But Why?

Even electric eels shock themselves frequently.
Electricity in water (ESPECIALLY salt water) is very dangerous. As explained in this Quora article:
The electricity will 'flow' to a low-energy position. This doesn't exclude the direction the mer-person is firing their weapon from.
Therefore, it would be just as dangerous to the mer-person using the weapon as it would be to the target of the attack.

Is There Hope?

Theoretically, (and this is a big theoretical, I didn't find any articles on this) if your mer-person had a resistance to electricity and a device that created a mid-energy field around them that they could tolerate, the ions would be more likely to flow in the opposite direction, in a way pushing the electric pulse in the right direction...
once it had initially started flowing away from the mer-person, there is nothing stopping it from spreading out rapidly. Thus, the weapon might be good short-range, but largely ineffective at longer ranges.

A More Likely Use

Tesla traps. These could be amped up to extremes and be placed around the outskirts of a mer-village. Then they could be turned on from a safe distance and obliterate anything that comes close to them.


As the question only mentions weapons and not guns or projectile weapons, which would have obvious drawbacks in water as the propelled object faces a lot more resistance in water, how about your classical tridents?

Make the rod non-conducting to save the person wielding it (both from the rod and by the rod (distance to target)), while having one of the pointy things be a cathode and the other an anode. Then you just need to penetrate or get close to your enemy with the pointy end and you should be able to stun.

And as a bonus it already fits into the concept of merpeople who are regularly using those objects. Plus it might get around the fact that any non-merpeople person is probably wearing a suit which in the worst case is serving them as a Faraday's cage.


Jules Verne already had a concept for such a weapon in 1870.

It wasn't used by mermaids, but by humans who exiled themselves to an almost completely underwater lifestyle. Because friction in the water would slow down bullets very quickly, they used guns which relied not on kinetic impact, but on an electric charge. The "bullet", fired with compressed air, upon striking the target, would deliver a high-voltage electric discharge, the purpose was to make the bullets lethal even if they lost almost all their kinetic energy. For bonus point, they worked well out of the water too.


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