Advanced aquatic warfare

[LonewandererD]

Hey guys, when I was working on the underwater civilisation challenge i got to thinking what the future arsenal of underwater warfare be like. I'm trying to map an underwater battle around an aquatic colony and want to know what would or wouldn't be feasible/practical underwater weaponry.

I know that ballistic weapons are basically useless underwater, the water provides too much resistance as to greatly reduce weapon range and water pressure on the weapon would prevent spent cases/shells being ejected thus jamming the gun. Weapons like missiles and rockets would useless again because of the extra resistance and because the water would flood their engines prevented them from igniting. Self propelled weapons like torpedoes or using sinking bombs obviously would work but here is a list of futuristic ideas I haven't found a lot of info on in my research. As these weapons would be used by a civilisation that is much more advanced than ours it could be argued that they can find a way around the smaller drawbacks of being underwater so I'm only asking if the technology was advanced enough would the following items THEORETICALLY work or not?

Electromagnetic Weapons (Railguns, coilguns): I know that electromagnetic engines on water vessels are thereoretically possible but what about weapons. If the electromagnets could be properly shielded as not to electrocute anyone close to the damn thing would it work underwater or would a propelled slug have the same drawbacks as ballistic weapons? I also known that electricity loses energy as its forced through water (unless its salt water) if you could create a highly focused "lightning" cannon would it work.

Energey/Beam Weapons: I know lasers can be used underwater and that water refraction does reduce their effectiveness as the beam becomes scattered. Assuming that you could get a good high-yield energy source/generator and could focus the beam to mitigate scatter would beam weapons be plausible, and if so what range would they have?

Sonic/Shockwave Weapons: I have hopes for this one as I know water is great for transferring shockwaves. If you could fire a focused cone of sonic energy or any form of focused directional shockwave what usefulness (if any) would it have underwater.

Magnet bombs: Instead of using electromagnets to propel a projectile could one be used as a weapons, like firing a dormant and very powerful magnet at an enemy ship and activating it to try and cause the metal skin to rip away towards the magnet to create hole breaches or causing ships to implode in on themselves if the magnet activate inside the ship.

Any insight would be most welcomed.

-D-

[Gamerprinter]

While you're discounting self-propelled weapon systems like torpedoes, I prefer a similar solution. Think in terms of remotely operated vehicles used in warfare today, or think of it in terms of an aircraft carrier with squadrons of 'intelligent robot submarines'.

I'm no physicist, you'd need someone like Torstan, or some willing to Google-fu it. Sonic is probably more effective, but how is focused sonic attacks affected by hydrodynamics (does the sound just spread anyway?) - I can't say. Your other options may or may not be effective either, I don't know.

I like 'intelligent robot submarine bombs'!

GP

[Ghostman]

How about tiny stealth drones? Too small and quiet to be easily detected by sonar, they latch on to your sub's hull and drill through it or otherwise damage it's systems.

[Hai-Etlik]

Rocket engines are (depending on the design) quite capable of operating underwater. As for an advanced underwater weapon, I'd go for a rocket propelled supercavitating torpedo. Russia actually has them in service: http://en.wikipedia.org/wiki/VA-111_Shkval

I'm not too familiar with hydrodynamics, but it might be possible to make small supercavitating missiles suitable for personal weapons.

Lasers suffer from significant attenuation under water. Certain frequencies are better but still suck. The same problems that prevent us from using laser weapons IRL still apply under water, except for cooling. It might be possible to get something usable.

The problem with slugthrowers is drag. If they have lower energy, they survive, but don't go very far, and if they have high energy, they disintegrate, and don't go very far. Switching to electromagnetic slugthrowers would not help. That's why in real life, dart/spear guns are used. They have a lot more mass than a bullet, are much thinner for their size, and travel MUCH slower, and that's why they are able to work.

I can't see the magnet thing working at all, as a mounted weapon it would have virtually no range, be stupendously mass and energy intensive, and would do more damage to the mounting ship than to any target. As a bomb, again it has virtually no range, would be stupendously heavy and energy demanding, and a plain old explosive would work far better in just about every way.

[RobA]

In term of low tech how would this work:

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A gear on the back so this can be accelerated to a high rotational velocity (in air?) then launched into water, letting the screw drive pull it?


And regarding sonic/shockwave, I could imagine a weapon that would generate a series of shockwaves at different frequencies from different location designed to meet all in phase and combine to an extremely intensive wave. I'm thinking of the liquid based version of a beat frequency.

-Rob A>

[torstan]

Agreed, the supercavitating torpedo is probably the best bet. You could sci-fi it up and have lasers on the nose to evaporate the water in front of the torpedo to have it flying in a gas bubble.

Then some form of automated exploding drone would work, with a high yield explosive. If you alter the supercavitating technology to work on small ships, then you have small and extremely fast attack drones that can outrun conventional weapons. Get close, then explode - or release magnetic limpet mines and run away.

Something more exotic might be to have some large ship that could aerate the water in a column, reducing the density of a column of water. That might be able to sink a ship or disable a submarine? Just some thoughts - no idea how you would make that work.

[waldronate]

One important detail about the supercavitating torpedoes is that they travel faster than the speed of sound in the medium. If you're relying on sound for detection of threats, then you'll be dead before you can deploy countermeasures.

EM scatters very quickly in dense media (in a very wavelength-dependent fashion). Sunlight, for example, is pretty much gone in the upper hundred meters of the ocean. I wouldn't count on being able to deliver any real amount of energy beyond a few tens of meters in seawater.

Straight electrical is also unlikely to work because it will flow towards the nearest ground. In the case of conducting seawater, that will be in all directions.

Any mass without an onboard propulsion source is unlikely to do well in a high-density environment like water. There's just too much mass to push out of the way that will eat into the energy budget. This problem does suggest either stealthy things like fish-analogs with onboard explosives or very fast things such as rockets that boost themselves along the way.

[Ryan K]

An advanced weapon doesn't merely rest upon the virtues of it's payload or the delivery of it's payload. Any weapon that can knock down it's competition by the virtue of being able to look first, shoot first, outrun, outgun, outmanouevre and outperform it's competition, or any combination of the above, is enough to be sufficiently advanced. Take any contempory weapons system and justify the ability for it's performance parameters to be expanded or improved, and it will be sufficient enough to be a game-changer in underwater warfare.

Indeed, UUVs are looking like the way of the future, as they don't have to worry so much about pressurised hulls and the meat-bags inside. This is handy when you want to outmanouvre a conventional sub, because if a sub goes to depth to avoid detection from sonar, these happy little chaps could be lying in wait to commit more souls to Davy Jones's locker. They can loiter in waterways for greater periods of time, years if need be. They would have passive detection, with highly complex computers to tell the difference between a school of fish, whales or pressurised hulls. They would be like the old sea-mines of now and the last century, only when they activate, they slowly move towards the threat and do nasty things to it. Mines with minds.

But for more sexier ideas, take ideas from nature. Materials that offer structural strength at depth, but are soft enough to be malleable to form precise hydrodyamic control surfaces, can form the basis of subsurface fighter subs that can patrol under the water at a great rate of knots. If you want to be even more advanced, have these fighters able to deploy from the sky like a seabird, strike underwater facilities, and then burst forth once again to RTB.

But yeah, as for actual weapons systems, there isn't much that is new under the sun. Rockets, torpedos, all good stuff. All that they need are expansions to their performance envelopes.

[rdanhenry]

Nanomachines that eat through enemy subs, but not your own. Flood the sea with them.

[Freax]

supercaviation has been mentioned...
Being stealthy is easier in water, because water blocks radar and heat signatures pretty well, and you can't look that far.
Sound is a problem.
You need of course sound-absorbing materials to avoid Sonar reflections, but some kind of clever foam or rubber could solve that.
Your own noises travel far, but this also could work for you, because you can hide in front of the background noise from all over the world if you are silent enough.
For high-distance-attacks that have time (like against a big ship with a known future location, a fixed station, ...) a weapon-system could drift with the current or even hang onto a large animal and only cover "the last mile" with a short, high-velocity run. When the enemy can detect it, it already is to close to be stopped.
Working in a swarm would probably also help to avoid counter-measures, because an enemy could tell that something is there, but the exact locations would be hard to determine when there are 100 tiny noise sources.
There have been several attempts to train animals to attack enemys, or even to make them controllable through electrodes in the brain. Mastering that also would constitute as advanced (not so much from the moral, but from the technological point of view).