Flechette, underwater projectiles.

[silent meadow]

Flechette are fin-stabilized dart like projectiles which are fired from non-rifled barrels. The idea is to add another projectile type which is good for submarines or other underwater vehicles.

To make this idea work there is going to be a new mechanic where projectiles get dramatically increased drag once they enter water.

Flechette cap - decreases accuracy but also greatly decreases the drag of underwater projectiles (effectively increasing the range/speed of underwater projectiles.)

Flechette body - adds kinetic damage and a slight amount of AP. Each body placed in a straight uninterrupted line behind the cap also further decreases the drag of the projectile. (also visually elongates the cap/spike for looks)

Fin stabilizers are also more affective underwater to make up for the cap's decreased accuracy. If the projective exits the water, this benefit is lost and the projectile starts to stray off-course.

Underwater projectiles could also take increased drag based on their diameter. So a 20mm Flechette is going to travel much further than a 200mm Flechette, because of the extra surface area. This makes them more realistic and also decreased their effectiveness on larger guns.

The extra drag could also be applied to non-Flechette projectiles to add a cool affect where machine gun bullets travel further in the water than large shells.

https://en.wikipedia.org/wiki/Underwater_firearm
Wikipedia article I read for the idea.

[errant iris]

doesn't this also exist for aps

[winter mulch]

Yeah, you have your supercavitation base and stabilizer fin bodies

Additionally, high velocity projectiles without supercav work underwater.

[dreamy sequoia]

aps already does this

[faint pollen]

"To make this idea work there is going to be a new mechanic where projectiles get dramatically increased drag once they enter water."
This was a thing even before APS existed.

[slim horizon]

literally is just supercavitation bodies and fin body

and the already insane drag shells have underwater

[river onyx]

supercav but you have to dedicate your entire shell to it to use it effectively

[silent meadow]

I've been making a submarine for like 2 days and I honestly had no idea that there was already slow-down in water. It's so unnoticeable that I didn't know it existed until I started looking for it.

Still, just adding a Supercavitation base is boring. There's no gameplay to just adding another module to your shells and waving your sub-aquatic problems goodbye.

[silent meadow]

To be more specific I have noticed it on crams but it's pretty negligible with advanced cannons

[winter mulch]

Aps is complicated as is. No need to increase complexity

[analog aurora]

Yeah aps is already a very complex system

The main issue with fighting underwater stuff is detection, anyways

[analog aurora]

Oh if you're on the other end slinging those aps shells you will definitely notice shells skimming the water and then ricocheting into space, missing the target entirely

Water skims and slow down is relevant in combat, not always relevant enough to force a switch to supercav base but it's a thing

[pearl gazelle]

Me when sabot supercav

[slender flare]

literally just sabot supercav

[royal maple]

lol i was literally about to say supercav before seeing this said literally seven times

[hushed helm]

The Yamato had these for special Anti Aircraft shells that would be filled up with these things turning the 18" guns into a shotgun.

[winter mulch]

Did someone say lag?

[slim horizon]

that's just a frag shell with a narrow cone° and a time fuse lmao

[analog orbit]

that's just a frag shell with-

[worthy shale]

Reminds me of the shotguns in Cruelty Squad, as they all use flechettes instead of any kind of pellets
Oh, and the dreaded flechette golem