Alright, that's cool Clock. I'll keep this on hold then until Friday evening then, it'll be a good break for me while I get real life stuff in order.
Bos, you're right. I didn't provide a lot of detail, so here's a quick rundown of the technology is like in TSS.
Weapons - The standard in most militaries of the age is laser weapons because of their ability to pierce armor. Think the stuff you see in Star Wars, and that's pretty much what it's like in TSS. (One change is that the lasers move at the speed of light, so they look more like glowing lines than projectiles) Projectile weapons are still in use, mostly among groups that can't afford fancy laser weapons. They're simpler and pack a punch, but have a hard time piercing modern armor. They can be propelled using either old fashioned gunpowder, or magnets. (See railgun and coilgun)
Armor - Military armor is mostly made out of plasteel, a material made of a composite plastic and interwoven steel thread. It's very malleable and very resilient to physical and laser damage. It's also very expensive. Civilian armor is still made of kevlar, the bulletproof synthetic fiber. Other, more rare armors include spaced armor, where two pieces of material are used with a bunch of space between them to break up bullets before they hit the target, and reflective armor which looks like a space blanket but functions to reflect lasers instead of absorbing them.
Other stuff - It's a sci-fi setting, so anything that seems at home there is probably gonna appear here. Some examples are sights that can see in the dark/through thin walls, guns that shoot tiny rockets instead of bullets, gloves with shock pads running through them, eyepieces that can tell if another person is lying by analyzing their heart rate at a distance, or even a sword that can be as flexible as rubber or strong as steel depending on if the blade is powered.
The general rule of thumb is that it needs to have at least a little rooting in reality, i.e. no explicitly magic spells or anything that far out there, but other than that the sky is the limit and creativity is welcomed.
As for the SCUBA gear in specific, a rebreather is a device that recycles air so you can breath pretty much forever. The gear Samar has just feeds air in from a tank, and will stop working if the tank runs out of air or is ruptured. Modern gear varies on their use of those. It's obviously cheaper to use a tank, especially on short expeditions, but for long periods underwater/in space rebreathers are preferred.
Your character can definitely rig a rebreather up in a couple days or so and still have time to spare, so take that as you will.
I hope that cleared it up a little bit, and I apologize if I'm getting too sciencey. TSS is a hard sci-fi setting, but the last thing I want is for the game to get bogged down/stop being fun by me trying to keep everything scientifically accurate. I try to follow the rule that if it's more fun without the science, then I should ignore the science, but I can lose sight of that sometimes. If you catch me doing something lame, lemme know. This is a game after all, and I want you guys to have fun playing it.