Underwater battles might be limited to close combat OR I might have to make it like one side tends to fight from a ship and another tends to fight from the water and throw things up to the ship. Or, everyone fights using a ship and the only advantage both sides have is that it doesn’t matter if they fall into the water because they can swim and breathe.
But if they do all end up in the water and want to fight, is there really no way for them to throw things at each other from far away? The biggest issue is that underwater slows things down.
I thought maybe something with a propeller would work. Like some kind of propeller you pull back with a rope and shoot it from a stick. The propeller would be sharp. It would whisk through the water and corkscrew into the enemy.
But I was talking with my partner and he doesn’t think a propeller-type weapon would be strong enough.
One other possible option was to somehow use water force. There’s apparently a type of shrimp or something that uses water pressure to stun its prey. But then again, that would probably not be effective for long range.
So, the last option was somehow they use sound to harm their enemies.
I don’t know how.
Any wild ideas? This is a fantasy story, so I could say “well, magick”, but I don’t want to if I possibly can.
Go watch some Black Panther 2 clips and adopt some ideas from them? Their nation was more advanced than land nations, so they had more in-depth weapons and some of them used sound while others could maybe adopt portions of animals like jellyfish with their stingers or something. Who is to say that they haven’t figured out gravity underwater already?
At first I was going to suggest something akin to torpedos, but since it’s sirens I’m now thinking that making use of natural features would be more realistic. Like they could somehow use thermal vents as weapons? And of course songs and sound, like the others have said. What about weapons that various real life sea creatures use, like poisonous spines, squirting ink, claws, etc.? I’d google for most dangerous sea creatures or something similar and see what comes up. Also making use of volcanoes like Narb suggested, or earthquake faults under the ocean. Volcanoes and earthquakes can generate various conditions like tidal waves, etc. that could be weaponized. Good luck figuring something out! ( ˆ◡ˆ)۶ ٩(˘◡˘ )
How about sound as a underwater weapon. Submarines use active sonar to protect themselves from hostile divers. The sonar pulse can liquify organs at a hundred-or-so meters distance…The exact effective range is highly classified, but the pulse is quite strong (don’t snorkel near submarines)…
There’s also depth charges, acoustic-homing weapons (e.g. torpedoes), cavitation weapons that produce a pocket of air around the weapon (air is easier to pass through than water), or water pressure itself. A cubic meter of water weighs one-tonne, and water hates being compressed…it will compress everything around it instead…
During the Second War, the British Coastal Command discovered that 20mm Armour-piercing rounds could travel through water and penetrate the hulls of ships below the waterline. The standard Armour-piercing rocket acted like a miniature rocket-propelled torpedo in the water too (with the same effect). In the gun-camera clips below, the bullet and rocket impacts in the water around the ships were not bad aiming, they’re a preferred means of sinking the ships.
The RAF also fitted a Mosquito fighter with a 6pdr anti-tank gun for dedicated anti-shipping work (the Mosquito Mk XVIII). One of these Mosquitoes sank a U-Boat hiding at periscope depth…The cannon shell travelled several feet into the water and passed through both sides of the U-Boat’s hull…
Adding to the above, how about the ability to summon rogue waves or the underwater equivalent (rogue tidal surges?).
I learnt a while ago that most large vessels (cargo ships, ocean liners, Navy ships) are designed to survive wave impact forces of ten-tonnes per square meter. However, rogue waves can deliver up to a hundred-tonnes per square meter of impact pressure. Enough force to ‘slice’ a cargo ship in half.
To paraphrase a somewhat related quote about the Titan submersible. When subjected to this kind of fluid pressure, your body undergoes a significant instantaneous transition: from biology to physics.