"Try scuba" is perhaps the closest one can get to "trying scuba on like a pair of shoes." It's perhaps pricey, compared to a lot of other activities. I had my first scuba-experience as part of a college "adventure" course. (Thinking back, that course was amazing, we did knot-tying horse-back riding, and a bunch of other random stuff)
That theoretically shouldn't be an issue you have to worry about, assuming you follow your training, and buy new, or have used equipment properly serviced.
Regulators were the one component I thought was VERY pooly explained. I'm a technical person, and even a mechanical person, and I barely understood what that spaghetti-mess was beyond how to use each hose or device.
These days I more fully understand it's not "a regulator" but rather individual components, connected by hoses, and that these components can be swapped with ease. (for the most part) Just make sure if you do, it's slightly more than hand-tight using a tool.
- 1st Stage Regulator: The thing that hooks up to your tank. It distributes air to everything else. It also has two pressure outputs. (1) Tank-pressure (i.e. 3000 psi) which goes to your SPG. (2) Regulated pressure, around 135 to 140psi.
- 2nd Stage Regulator: The thing you breathe out of. This also brings pressure down from 140psi to around ambient pressure - or the pressure of the water around you.
- Octo: An "octo" just another backup/extra 2nd stage. Nothing special about an octo, other than it may have a yellow face plate. You can use practically any 2nd stage, though you might as well go cheap.
- SPG: A gauge that measures air-pressure from the tank.
- Hoses: Hoses can be swapped as needed. You can get longer or shorter hoses.
- There are kinda 3 hose types. (1) High-pressure hose, which goes to your SPG or any pressure-monitoring device. (2) Low pressure hose, which goes to your regulators and (3) BCD hose which is a hose with an integrated quick release.
- BCD hose: Allows you to inflate your BCD (or dry-suit) from your tank. These can be swapped, if the quick-release is incompatible with your BCD.
- For hoses, you can get different colors of hoses. Different lengths of hoses. You can also get "flex hoses."
- Port Plugs: Your first stage may have a number of high-pressure and low-pressure ports. Inside any unused port is a port-plug. You can add or remove devices by removing-or-adding port plugs. You can even swap which port one of your devices is screwed into.
Features:
- Environmentally sealed: Without this, water enters your first stage, and water-pressure is used to help balance the pressure against ambient-pressure. With this, water does not enter the first stage. (Usually, there's a rubbery seal on the outside, and silicone-grease on the inside, and pressure is "transmitted" that way). One advantage of this is reducing salt-water corrosion. Also helps with very cold water, though not required.
- Cold Water: Some regulators are designed for cold-water use. Probably not worth worrying about, unless you intend to dive in below-50f waters.
- Balanced: Breathes nicer usually. I'll let someone else describe this.
- 2nd stage knobs - One allows you to adjust how easy it breathes or goes into free-flow. Another is Venturi assist, which can also help it breathe easier. These aren't super-important, and to be honest I almost always forget they exist when on a dive.
- Piston vs Diaphragm - It's the component which helps your first-stage "know" when your regulator has reached the 140psi and needs to stop. I don't think new scuba-divers need to worry about this.
I'm probably missing stuff, and there are probably a couple very minor highly-technical inaccuracies or wrong-terms in there that I'm sure people will correct me on, but this should help a new-ish diver get started.
