How viable are underwater combat frames?

[Zero Revenge]

We've all seen the underwater frames that people have shared on the forums. My question is more to the viability to "Underwater Combat Frame". It's a common mecha trope that I absolutely love, aquatic combat, but how does it work in the Solar Calendar? Part of this stems from my own ignorance concerning actual underwater combat specifics, but how deep could a presumed frame go underwater? Laser/Pulse weapons, a common occurrence in the S.C., do they work underwater at all? At reduced efficiency?

Without just saying "realism be damned", I would like to know the capabilities of aquatic frames. Arcadia due to start aquatic combat (using the rule in the books for a dedicated aquatic systems), and before we go crazy with the fluff, I'd like to know the parameters we have to play with.

[gusindor]

For those who don't know: Frames operating in hostile environments, such as space, underwater, extreme temperatures etc. only get one white die. However, they can have equipment that lets them have two white dice as per normal. Environmental equipment (someone should give it a cooler name) acts just like any other system, taking up one of a frame's four slots and getting disabled by damage.

I forget whether this is in the rulebook or just a popular house-rule. What counts as a "hostile environment" is open to some interpretation, but space and water are generally accepted. Deserts, marshlands, tundra, volcanoes, high- or low-gravity planets, inclement weather, vertical surfaces (can you imagine a battle on the side of a cliff?) radiation, and other weirdness are also possible.

Anyway, to me that seems to imply that mobile frames can work just fine in at least some amount of water, but most of them aren't very graceful swimmers. No idea how deep they can go, but I imagine most frames are tough enough to withstand pressures that would be harmful to humans.

In all this, I am assuming the pilots have enough air, and any tech that would jam or short out is properly sealed. Either of these could be your environment system, or you could decide as a group that they're ubiquitous enough to not count.

Based on my limited understanding of how light behaves in water, it seems like laser-based weapons would function, but there would be some difference in the way the beam travels that takes some getting used to. Something about refraction that a veteran knows how to compensate for, but throws off a rookie's aim.

Physical weapons might be a bit slower or less precise if they weren't designed to move through water, but in principle they'd work just the same.

I have no idea how plasma behaves in water.

There are substances that burn just fine underwater, so fire is still technically an option. Heat might be a concern, I'm not sure. I don't know what effects boiling the water around you would have, or what could cause that, but I know it wouldn't be pleasant.

Similarly, electric, cryogenic, or corrosive weapons would probably not work as intended, although if used properly they could be devastating. Weapons that use fluids, like an acid gun, glue gun, flamethrower (whether they shoot burning gas or liquid), or whatever else you invent, would need to take into account all sorts of complicated physics. Magnetic, vibration and other weapons that don't actually shoot anything would probably work just fine.

[Soren]

Blue-green lasers work perfectly underwater. Supercavitating torpedoes and jetguns, too. Be creative.

Counterpart to the hostile environment rules, you can build specialists that require an attachment to operate outside the (water/vacuum/volcano/etc), which are presumably pretty good in those environments. Just please, deploy something more effective than an Aqua GM.

[Zero Revenge]

Blue-green lasers work perfectly underwater. Supercavitating torpedoes and jetguns, too. Be creative.

I wasn't sure on lasers working underwater, but alright! We've made up a few weapon ideas, flechette rifles, etc, but I just wanted to make sure there wasn't any glaring "no's" outside of the obvious.

Just please, deploy something more effective than an Aqua GM.

Ha! Absolutely. That always kinda bothered me. The Federation made the Zaku Mariner after all, they clearly know how to make a half-way decent aquatic MS. So, why were they still using OYW Aqua GM's? ...Aside from making the Capule look good...

[Mantisking]

Paradox Boy had a couple of underwater designs. I had a submersible Block Chest design.

[addking]

I think Malcolm Craig and af/ny each had an underwater frame or two? And I recall someone did a full company as well. Might want to trawl thru the flickr group.

[Zero Revenge]

I appreciate you guys linking to aquatic frames, I was more concerned of the technology and in-universe science behind it, not rules or designs.

[Joshua A.C. Newman]

Ok, so then!

Underwater mecha are an IRL thing. More than once, even!

What they have to deal with are:

• Pressure (usually dealt with by having internal atmosphere separating the diver from external pressure.
• Manipulation of objects, given that the human hand is a pretty remarkable tool
• Cold and dark (dealt with the same way as the pressure)
• Lack of air/oxygenation

You'll notice that these issues are also addressed by using a labor frame! Something that does one of these in an obvious way would be your special underwater system.

Additionally, mobile frames have to fight, so they need to:

• Move quickly
• Sense
• Fire weapons
• Hide and defend themselves

Quick movement can be dealt with thrusters.

Sensors and communication are more sound-based than radio, since radio range underwater is very short.

Weapons, as Soren suggests, are supercavitating ammunition like the Shkval:



...or blue-green lasers.

Explosives are particularly dangerous underwater. So, in such an environment, I might want to make a special rule about SSRs (really, SSTs): for every frame within 1 of the place it hits (including the target), they roll a die. On a 6, they take one hit. That's because torpedoes generally work with a proximity fuse, and actually do damage with the shockwave traveling through the water. Tactically, of course, this means that you want to keep your frames separate from each other. And when you see two of them huddled behind an outcropping, take your shot!

[Zero Revenge]

Alrighty, this is what I was looking for. Thank you very much Joshua for your time & help! I'll let the group decide on the SST ruling too.

And I guess the blue-green lasers wasn't a joke eh. I guess I should study up on lasers. I just figured you guys were kidding on lasers underwater. XD

[soriansj]

One of the things I learned in the Navy is about a "Delta" fire, which is Navy classification for Magnesium (commonly used on aircraft) Fire. The thing about magnesium is that once it catches fire, usually from an explosion (say like from a rocket or torpedo), it is nearly impossible to put the fire out. You can douse it or even submerge by jettisoning overboard and the fire will continue to burn. That's because magnesium that's on fire creates its own oxygen, even while completely submerged.

We could use this as a basis for weaponry or damage.

Sent from my SGH-T399 using Tapatalk

[gatlinggouf927]

Well, this has inspired me to work on some new designs, thanks for the tips guys!

Also still laughing from Soren's Aqua GM comment XD

Also Rob, look into Mars Daybreak, If i'm not mistaken it deals exclusively with underwater mecha

[Zero Revenge]

Well, this has inspired me to work on some new designs, thanks for the tips guys!

Also still laughing from Soren's Aqua GM comment XD

Also Rob, look into Mars Daybreak, If i'm not mistaken it deals exclusively with underwater mecha

1.) God Dammit.
2.) Aye, it was a goodie. Dumb, poor Federation.
3.) We watched Mars Daybreak at Tom's that one night. It seemed cool, just never followed through though.